#include <cmath>
using namespace llvm;
-namespace {
- // Hidden options for help debugging.
- static cl::opt<bool> DisableReMat("disable-rematerialization",
- cl::init(false), cl::Hidden);
-
- static cl::opt<bool> SplitAtBB("split-intervals-at-bb",
- cl::init(true), cl::Hidden);
- static cl::opt<int> SplitLimit("split-limit",
- cl::init(-1), cl::Hidden);
-}
+// Hidden options for help debugging.
+static cl::opt<bool> DisableReMat("disable-rematerialization",
+ cl::init(false), cl::Hidden);
+
+static cl::opt<bool> SplitAtBB("split-intervals-at-bb",
+ cl::init(true), cl::Hidden);
+static cl::opt<int> SplitLimit("split-limit",
+ cl::init(-1), cl::Hidden);
STATISTIC(numIntervals, "Number of original intervals");
STATISTIC(numIntervalsAfter, "Number of intervals after coalescing");
STATISTIC(numSplits , "Number of intervals split");
char LiveIntervals::ID = 0;
-namespace {
- RegisterPass<LiveIntervals> X("liveintervals", "Live Interval Analysis");
-}
+static RegisterPass<LiveIntervals> X("liveintervals", "Live Interval Analysis");
void LiveIntervals::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addPreserved<LiveVariables>();
}
void LiveIntervals::releaseMemory() {
+ MBB2IdxMap.clear();
Idx2MBBMap.clear();
mi2iMap_.clear();
i2miMap_.clear();
delete ClonedMIs[i];
}
-/// runOnMachineFunction - Register allocate the whole function
-///
-bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) {
- mf_ = &fn;
- mri_ = &mf_->getRegInfo();
- tm_ = &fn.getTarget();
- tri_ = tm_->getRegisterInfo();
- tii_ = tm_->getInstrInfo();
- lv_ = &getAnalysis<LiveVariables>();
- allocatableRegs_ = tri_->getAllocatableSet(fn);
-
+void LiveIntervals::computeNumbering() {
+ Index2MiMap OldI2MI = i2miMap_;
+
+ Idx2MBBMap.clear();
+ MBB2IdxMap.clear();
+ mi2iMap_.clear();
+ i2miMap_.clear();
+
// Number MachineInstrs and MachineBasicBlocks.
// Initialize MBB indexes to a sentinal.
MBB2IdxMap.resize(mf_->getNumBlockIDs(), std::make_pair(~0U,~0U));
i2miMap_.push_back(I);
MIIndex += InstrSlots::NUM;
}
-
+
+ if (StartIdx == MIIndex) {
+ // Empty MBB
+ MIIndex += InstrSlots::NUM;
+ i2miMap_.push_back(0);
+ }
// Set the MBB2IdxMap entry for this MBB.
- MBB2IdxMap[MBB->getNumber()] = (StartIdx == MIIndex)
- ? std::make_pair(StartIdx, StartIdx) // Empty MBB
- : std::make_pair(StartIdx, MIIndex - 1);
+ MBB2IdxMap[MBB->getNumber()] = std::make_pair(StartIdx, MIIndex - 1);
Idx2MBBMap.push_back(std::make_pair(StartIdx, MBB));
}
std::sort(Idx2MBBMap.begin(), Idx2MBBMap.end(), Idx2MBBCompare());
+
+ if (!OldI2MI.empty())
+ for (iterator I = begin(), E = end(); I != E; ++I)
+ for (LiveInterval::iterator LI = I->second.begin(), LE = I->second.end();
+ LI != LE; ++LI) {
+
+ // Remap the start index of the live range to the corresponding new
+ // number, or our best guess at what it _should_ correspond to if the
+ // original instruction has been erased. This is either the following
+ // instruction or its predecessor.
+ unsigned offset = LI->start % InstrSlots::NUM;
+ if (OldI2MI[LI->start / InstrSlots::NUM])
+ LI->start = mi2iMap_[OldI2MI[LI->start / InstrSlots::NUM]] + offset;
+ else {
+ unsigned i = 0;
+ MachineInstr* newInstr = 0;
+ do {
+ newInstr = OldI2MI[LI->start / InstrSlots::NUM + i];
+ i++;
+ } while (!newInstr);
+
+ if (mi2iMap_[newInstr] ==
+ MBB2IdxMap[newInstr->getParent()->getNumber()].first)
+ LI->start = mi2iMap_[newInstr];
+ else
+ LI->start = mi2iMap_[newInstr] - InstrSlots::NUM + offset;
+ }
+
+ // Remap the ending index in the same way that we remapped the start,
+ // except for the final step where we always map to the immediately
+ // following instruction.
+ if (LI->end / InstrSlots::NUM < OldI2MI.size()) {
+ offset = LI->end % InstrSlots::NUM;
+ if (OldI2MI[LI->end / InstrSlots::NUM])
+ LI->end = mi2iMap_[OldI2MI[LI->end / InstrSlots::NUM]] + offset;
+ else {
+ unsigned i = 0;
+ MachineInstr* newInstr = 0;
+ do {
+ newInstr = OldI2MI[LI->end / InstrSlots::NUM + i];
+ i++;
+ } while (!newInstr);
+
+ LI->end = mi2iMap_[newInstr];
+ }
+ } else {
+ LI->end = i2miMap_.size() * InstrSlots::NUM;
+ }
+
+ // Remap the VNInfo def index, which works the same as the
+ // start indices above.
+ VNInfo* vni = LI->valno;
+ offset = vni->def % InstrSlots::NUM;
+ if (OldI2MI[vni->def / InstrSlots::NUM])
+ vni->def = mi2iMap_[OldI2MI[vni->def / InstrSlots::NUM]] + offset;
+ else {
+ unsigned i = 0;
+ MachineInstr* newInstr = 0;
+ do {
+ newInstr = OldI2MI[vni->def / InstrSlots::NUM + i];
+ i++;
+ } while (!newInstr);
+
+ if (mi2iMap_[newInstr] ==
+ MBB2IdxMap[newInstr->getParent()->getNumber()].first)
+ vni->def = mi2iMap_[newInstr];
+ else
+ vni->def = mi2iMap_[newInstr] - InstrSlots::NUM + offset;
+ }
+
+ // Remap the VNInfo kill indices, which works the same as
+ // the end indices above.
+ for (size_t i = 0; i < vni->kills.size(); ++i) {
+ offset = vni->kills[i] % InstrSlots::NUM;
+ if (OldI2MI[vni->kills[i] / InstrSlots::NUM])
+ vni->kills[i] = mi2iMap_[OldI2MI[vni->kills[i] / InstrSlots::NUM]] +
+ offset;
+ else {
+ unsigned e = 0;
+ MachineInstr* newInstr = 0;
+ do {
+ newInstr = OldI2MI[vni->kills[i] / InstrSlots::NUM + e];
+ e++;
+ } while (!newInstr);
+
+ vni->kills[i] = mi2iMap_[newInstr];
+ }
+ }
+ }
+}
+/// runOnMachineFunction - Register allocate the whole function
+///
+bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) {
+ mf_ = &fn;
+ mri_ = &mf_->getRegInfo();
+ tm_ = &fn.getTarget();
+ tri_ = tm_->getRegisterInfo();
+ tii_ = tm_->getInstrInfo();
+ lv_ = &getAnalysis<LiveVariables>();
+ allocatableRegs_ = tri_->getAllocatableSet(fn);
+
+ computeNumbering();
computeIntervals();
numIntervals += getNumIntervals();
void LiveIntervals::print(std::ostream &O, const Module* ) const {
O << "********** INTERVALS **********\n";
for (const_iterator I = begin(), E = end(); I != E; ++I) {
- I->second.print(DOUT, tri_);
- DOUT << "\n";
+ I->second.print(O, tri_);
+ O << "\n";
}
O << "********** MACHINEINSTRS **********\n";
// live interval.
for (unsigned i = 0, e = vi.AliveBlocks.size(); i != e; ++i) {
if (vi.AliveBlocks[i]) {
- MachineBasicBlock *MBB = mf_->getBlockNumbered(i);
- if (!MBB->empty()) {
- LiveRange LR(getMBBStartIdx(i),
- getInstructionIndex(&MBB->back()) + InstrSlots::NUM,
- ValNo);
- interval.addRange(LR);
- DOUT << " +" << LR;
- }
+ LiveRange LR(getMBBStartIdx(i),
+ getMBBEndIdx(i)+1, // MBB ends at -1.
+ ValNo);
+ interval.addRange(LR);
+ DOUT << " +" << LR;
}
}
MIIndex += InstrSlots::NUM;
}
+
+ if (MBB->begin() == miEnd) MIIndex += InstrSlots::NUM; // Empty MBB
}
}
const MachineLoopInfo *loopInfo,
unsigned &NewVReg, unsigned ImpUse, bool &HasDef, bool &HasUse,
std::map<unsigned,unsigned> &MBBVRegsMap,
- std::vector<LiveInterval*> &NewLIs) {
+ std::vector<LiveInterval*> &NewLIs, float &SSWeight) {
+ MachineBasicBlock *MBB = MI->getParent();
+ unsigned loopDepth = loopInfo->getLoopDepth(MBB);
bool CanFold = false;
RestartInstruction:
for (unsigned i = 0; i != MI->getNumOperands(); ++i) {
}
}
- if (TryFold) {
+ // Update stack slot spill weight if we are splitting.
+ float Weight = getSpillWeight(HasDef, HasUse, loopDepth);
+ if (!TrySplit)
+ SSWeight += Weight;
+
+ if (!TryFold)
+ CanFold = false;
+ else {
// Do not fold load / store here if we are splitting. We'll find an
// optimal point to insert a load / store later.
if (!TrySplit) {
HasUse = false;
HasDef = false;
CanFold = false;
- if (isRemoved(MI))
+ if (isRemoved(MI)) {
+ SSWeight -= Weight;
break;
+ }
goto RestartInstruction;
}
} else {
+ // We'll try to fold it later if it's profitable.
CanFold = canFoldMemoryOperand(MI, Ops, DefIsReMat);
}
- } else
- CanFold = false;
+ }
// Create a new virtual register for the spill interval.
bool CreatedNewVReg = false;
return false;
}
-static const VNInfo *findDefinedVNInfo(const LiveInterval &li, unsigned DefIdx) {
- const VNInfo *VNI = NULL;
- for (LiveInterval::const_vni_iterator i = li.vni_begin(),
- e = li.vni_end(); i != e; ++i)
- if ((*i)->def == DefIdx) {
- VNI = *i;
- break;
- }
- return VNI;
-}
-
/// RewriteInfo - Keep track of machine instrs that will be rewritten
/// during spilling.
-struct RewriteInfo {
- unsigned Index;
- MachineInstr *MI;
- bool HasUse;
- bool HasDef;
- RewriteInfo(unsigned i, MachineInstr *mi, bool u, bool d)
- : Index(i), MI(mi), HasUse(u), HasDef(d) {}
-};
-
-struct RewriteInfoCompare {
- bool operator()(const RewriteInfo &LHS, const RewriteInfo &RHS) const {
- return LHS.Index < RHS.Index;
- }
-};
+namespace {
+ struct RewriteInfo {
+ unsigned Index;
+ MachineInstr *MI;
+ bool HasUse;
+ bool HasDef;
+ RewriteInfo(unsigned i, MachineInstr *mi, bool u, bool d)
+ : Index(i), MI(mi), HasUse(u), HasDef(d) {}
+ };
+
+ struct RewriteInfoCompare {
+ bool operator()(const RewriteInfo &LHS, const RewriteInfo &RHS) const {
+ return LHS.Index < RHS.Index;
+ }
+ };
+}
void LiveIntervals::
rewriteInstructionsForSpills(const LiveInterval &li, bool TrySplit,
BitVector &RestoreMBBs,
std::map<unsigned, std::vector<SRInfo> > &RestoreIdxes,
std::map<unsigned,unsigned> &MBBVRegsMap,
- std::vector<LiveInterval*> &NewLIs) {
+ std::vector<LiveInterval*> &NewLIs, float &SSWeight) {
bool AllCanFold = true;
unsigned NewVReg = 0;
unsigned start = getBaseIndex(I->start);
bool HasDef = false;
bool HasUse = false;
bool CanFold = rewriteInstructionForSpills(li, I->valno, TrySplit,
- index, end, MI, ReMatOrigDefMI, ReMatDefMI,
- Slot, LdSlot, isLoad, isLoadSS, DefIsReMat,
- CanDelete, vrm, rc, ReMatIds, loopInfo, NewVReg,
- ImpUse, HasDef, HasUse, MBBVRegsMap, NewLIs);
+ index, end, MI, ReMatOrigDefMI, ReMatDefMI,
+ Slot, LdSlot, isLoad, isLoadSS, DefIsReMat,
+ CanDelete, vrm, rc, ReMatIds, loopInfo, NewVReg,
+ ImpUse, HasDef, HasUse, MBBVRegsMap, NewLIs, SSWeight);
if (!HasDef && !HasUse)
continue;
HasKill = anyKillInMBBAfterIdx(li, I->valno, MBB, getDefIndex(index));
else {
// If this is a two-address code, then this index starts a new VNInfo.
- const VNInfo *VNI = findDefinedVNInfo(li, getDefIndex(index));
+ const VNInfo *VNI = li.findDefinedVNInfo(getDefIndex(index));
if (VNI)
HasKill = anyKillInMBBAfterIdx(li, VNI, MBB, getDefIndex(index));
}
std::vector<LiveInterval*> LiveIntervals::
addIntervalsForSpills(const LiveInterval &li,
- const MachineLoopInfo *loopInfo, VirtRegMap &vrm) {
+ const MachineLoopInfo *loopInfo, VirtRegMap &vrm,
+ float &SSWeight) {
// Since this is called after the analysis is done we don't know if
// LiveVariables is available
lv_ = getAnalysisToUpdate<LiveVariables>();
li.print(DOUT, tri_);
DOUT << '\n';
+ // Spill slot weight.
+ SSWeight = 0.0f;
+
// Each bit specify whether it a spill is required in the MBB.
BitVector SpillMBBs(mf_->getNumBlockIDs());
std::map<unsigned, std::vector<SRInfo> > SpillIdxes;
Slot, LdSlot, isLoad, isLoadSS, DefIsReMat,
false, vrm, rc, ReMatIds, loopInfo,
SpillMBBs, SpillIdxes, RestoreMBBs, RestoreIdxes,
- MBBVRegsMap, NewLIs);
+ MBBVRegsMap, NewLIs, SSWeight);
} else {
rewriteInstructionsForSpills(li, false, I, NULL, 0,
Slot, 0, false, false, false,
false, vrm, rc, ReMatIds, loopInfo,
SpillMBBs, SpillIdxes, RestoreMBBs, RestoreIdxes,
- MBBVRegsMap, NewLIs);
+ MBBVRegsMap, NewLIs, SSWeight);
}
IsFirstRange = false;
}
+ SSWeight = 0.0f; // Already accounted for when split.
handleSpilledImpDefs(li, vrm, rc, NewLIs);
return NewLIs;
}
Slot, LdSlot, isLoad, isLoadSS, DefIsReMat,
CanDelete, vrm, rc, ReMatIds, loopInfo,
SpillMBBs, SpillIdxes, RestoreMBBs, RestoreIdxes,
- MBBVRegsMap, NewLIs);
+ MBBVRegsMap, NewLIs, SSWeight);
}
// Insert spills / restores if we are splitting.
if (NeedStackSlot) {
int Id = SpillMBBs.find_first();
while (Id != -1) {
+ MachineBasicBlock *MBB = mf_->getBlockNumbered(Id);
+ unsigned loopDepth = loopInfo->getLoopDepth(MBB);
std::vector<SRInfo> &spills = SpillIdxes[Id];
for (unsigned i = 0, e = spills.size(); i != e; ++i) {
int index = spills[i].index;
if (!Folded) {
LiveRange *LR = &nI.ranges[nI.ranges.size()-1];
bool isKill = LR->end == getStoreIndex(index);
- vrm.addSpillPoint(VReg, isKill, MI);
+ if (!MI->registerDefIsDead(nI.reg))
+ // No need to spill a dead def.
+ vrm.addSpillPoint(VReg, isKill, MI);
if (isKill)
AddedKill.insert(&nI);
}
+
+ // Update spill slot weight.
+ if (!isReMat)
+ SSWeight += getSpillWeight(true, false, loopDepth);
}
Id = SpillMBBs.find_next(Id);
}
int Id = RestoreMBBs.find_first();
while (Id != -1) {
+ MachineBasicBlock *MBB = mf_->getBlockNumbered(Id);
+ unsigned loopDepth = loopInfo->getLoopDepth(MBB);
+
std::vector<SRInfo> &restores = RestoreIdxes[Id];
for (unsigned i = 0, e = restores.size(); i != e; ++i) {
int index = restores[i].index;
continue;
unsigned VReg = restores[i].vreg;
LiveInterval &nI = getOrCreateInterval(VReg);
+ bool isReMat = vrm.isReMaterialized(VReg);
MachineInstr *MI = getInstructionFromIndex(index);
bool CanFold = false;
Ops.clear();
// Fold the load into the use if possible.
bool Folded = false;
if (CanFold && !Ops.empty()) {
- if (!vrm.isReMaterialized(VReg))
+ if (!isReMat)
Folded = tryFoldMemoryOperand(MI, vrm, NULL,index,Ops,true,Slot,VReg);
else {
MachineInstr *ReMatDefMI = vrm.getReMaterializedMI(VReg);
nI.removeRange(getLoadIndex(index), getUseIndex(index)+1);
else
vrm.addRestorePoint(VReg, MI);
+
+ // Update spill slot weight.
+ if (!isReMat)
+ SSWeight += getSpillWeight(false, true, loopDepth);
}
Id = RestoreMBBs.find_next(Id);
}
}
}
}
+
+LiveRange LiveIntervals::addLiveRangeToEndOfBlock(unsigned reg,
+ MachineInstr* startInst) {
+ LiveInterval& Interval = getOrCreateInterval(reg);
+ VNInfo* VN = Interval.getNextValue(
+ getInstructionIndex(startInst) + InstrSlots::DEF,
+ startInst, getVNInfoAllocator());
+ VN->hasPHIKill = true;
+ VN->kills.push_back(getMBBEndIdx(startInst->getParent()));
+ LiveRange LR(getInstructionIndex(startInst) + InstrSlots::DEF,
+ getMBBEndIdx(startInst->getParent()) + 1, VN);
+ Interval.addRange(LR);
+
+ return LR;
+}
projects / oota-llvm.git / blobdiff