X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FLiveIntervalAnalysis.cpp;h=7a3b30511620665c3b8f80fc13af9bb55eb7e92a;hb=53c9e5fbb9492824adfa1b004c198236fba1a93b;hp=8177db61949450bb2cebf7b9b6272be1e21fad13;hpb=9030fc22dd73684901ecb749c9688e289bd1a777;p=oota-llvm.git diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp index 8177db61949..7a3b3051162 100644 --- a/lib/CodeGen/LiveIntervalAnalysis.cpp +++ b/lib/CodeGen/LiveIntervalAnalysis.cpp @@ -28,6 +28,7 @@ #include "llvm/CodeGen/Passes.h" #include "llvm/CodeGen/VirtRegMap.h" #include "llvm/IR/Value.h" +#include "llvm/Support/BlockFrequency.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" @@ -51,6 +52,14 @@ INITIALIZE_PASS_DEPENDENCY(SlotIndexes) INITIALIZE_PASS_END(LiveIntervals, "liveintervals", "Live Interval Analysis", false, false) +#ifndef NDEBUG +static cl::opt EnablePrecomputePhysRegs( + "precompute-phys-liveness", cl::Hidden, + cl::desc("Eagerly compute live intervals for all physreg units.")); +#else +static bool EnablePrecomputePhysRegs = false; +#endif // NDEBUG + void LiveIntervals::getAnalysisUsage(AnalysisUsage &AU) const { AU.setPreservesCFG(); AU.addRequired(); @@ -86,15 +95,15 @@ void LiveIntervals::releaseMemory() { RegMaskBits.clear(); RegMaskBlocks.clear(); - for (unsigned i = 0, e = RegUnitIntervals.size(); i != e; ++i) - delete RegUnitIntervals[i]; - RegUnitIntervals.clear(); + for (unsigned i = 0, e = RegUnitRanges.size(); i != e; ++i) + delete RegUnitRanges[i]; + RegUnitRanges.clear(); // Release VNInfo memory regions, VNInfo objects don't need to be dtor'd. VNInfoAllocator.Reset(); } -/// runOnMachineFunction - Register allocate the whole function +/// runOnMachineFunction - calculates LiveIntervals /// bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) { MF = &fn; @@ -115,6 +124,12 @@ bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) { computeRegMasks(); computeLiveInRegUnits(); + if (EnablePrecomputePhysRegs) { + // For stress testing, precompute live ranges of all physical register + // units, including reserved registers. + for (unsigned i = 0, e = TRI->getNumRegUnits(); i != e; ++i) + getRegUnit(i); + } DEBUG(dump()); return true; } @@ -124,15 +139,15 @@ void LiveIntervals::print(raw_ostream &OS, const Module* ) const { OS << "********** INTERVALS **********\n"; // Dump the regunits. - for (unsigned i = 0, e = RegUnitIntervals.size(); i != e; ++i) - if (LiveInterval *LI = RegUnitIntervals[i]) - OS << PrintRegUnit(i, TRI) << " = " << *LI << '\n'; + for (unsigned i = 0, e = RegUnitRanges.size(); i != e; ++i) + if (LiveRange *LR = RegUnitRanges[i]) + OS << PrintRegUnit(i, TRI) << ' ' << *LR << '\n'; // Dump the virtregs. for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) { unsigned Reg = TargetRegisterInfo::index2VirtReg(i); if (hasInterval(Reg)) - OS << PrintReg(Reg) << " = " << getInterval(Reg) << '\n'; + OS << getInterval(Reg) << '\n'; } OS << "RegMasks:"; @@ -162,9 +177,9 @@ LiveInterval* LiveIntervals::createInterval(unsigned reg) { /// computeVirtRegInterval - Compute the live interval of a virtual register, /// based on defs and uses. -void LiveIntervals::computeVirtRegInterval(LiveInterval *LI) { +void LiveIntervals::computeVirtRegInterval(LiveInterval &LI) { assert(LRCalc && "LRCalc not initialized."); - assert(LI->empty() && "Should only compute empty intervals."); + assert(LI.empty() && "Should only compute empty intervals."); LRCalc->reset(MF, getSlotIndexes(), DomTree, &getVNInfoAllocator()); LRCalc->createDeadDefs(LI); LRCalc->extendToUses(LI); @@ -175,9 +190,7 @@ void LiveIntervals::computeVirtRegs() { unsigned Reg = TargetRegisterInfo::index2VirtReg(i); if (MRI->reg_nodbg_empty(Reg)) continue; - LiveInterval *LI = createInterval(Reg); - VirtRegIntervals[Reg] = LI; - computeVirtRegInterval(LI); + createAndComputeVirtRegInterval(Reg); } } @@ -214,12 +227,10 @@ void LiveIntervals::computeRegMasks() { // interference. // -/// computeRegUnitInterval - Compute the live interval of a register unit, based -/// on the uses and defs of aliasing registers. The interval should be empty, +/// computeRegUnitInterval - Compute the live range of a register unit, based +/// on the uses and defs of aliasing registers. The range should be empty, /// or contain only dead phi-defs from ABI blocks. -void LiveIntervals::computeRegUnitInterval(LiveInterval *LI) { - unsigned Unit = LI->reg; - +void LiveIntervals::computeRegUnitRange(LiveRange &LR, unsigned Unit) { assert(LRCalc && "LRCalc not initialized."); LRCalc->reset(MF, getSlotIndexes(), DomTree, &getVNInfoAllocator()); @@ -229,25 +240,21 @@ void LiveIntervals::computeRegUnitInterval(LiveInterval *LI) { // idempotent. It is very rare for a register unit to have multiple roots, so // uniquing super-registers is probably not worthwhile. for (MCRegUnitRootIterator Roots(Unit, TRI); Roots.isValid(); ++Roots) { - unsigned Root = *Roots; - if (!MRI->reg_empty(Root)) - LRCalc->createDeadDefs(LI, Root); - for (MCSuperRegIterator Supers(Root, TRI); Supers.isValid(); ++Supers) { + for (MCSuperRegIterator Supers(*Roots, TRI, /*IncludeSelf=*/true); + Supers.isValid(); ++Supers) { if (!MRI->reg_empty(*Supers)) - LRCalc->createDeadDefs(LI, *Supers); + LRCalc->createDeadDefs(LR, *Supers); } } - // Now extend LI to reach all uses. + // Now extend LR to reach all uses. // Ignore uses of reserved registers. We only track defs of those. for (MCRegUnitRootIterator Roots(Unit, TRI); Roots.isValid(); ++Roots) { - unsigned Root = *Roots; - if (!MRI->isReserved(Root) && !MRI->reg_empty(Root)) - LRCalc->extendToUses(LI, Root); - for (MCSuperRegIterator Supers(Root, TRI); Supers.isValid(); ++Supers) { + for (MCSuperRegIterator Supers(*Roots, TRI, /*IncludeSelf=*/true); + Supers.isValid(); ++Supers) { unsigned Reg = *Supers; if (!MRI->isReserved(Reg) && !MRI->reg_empty(Reg)) - LRCalc->extendToUses(LI, Reg); + LRCalc->extendToUses(LR, Reg); } } } @@ -258,11 +265,11 @@ void LiveIntervals::computeRegUnitInterval(LiveInterval *LI) { /// without a corresponding def when entering the entry block or a landing pad. /// void LiveIntervals::computeLiveInRegUnits() { - RegUnitIntervals.resize(TRI->getNumRegUnits()); + RegUnitRanges.resize(TRI->getNumRegUnits()); DEBUG(dbgs() << "Computing live-in reg-units in ABI blocks.\n"); - // Keep track of the intervals allocated. - SmallVector NewIntvs; + // Keep track of the live range sets allocated. + SmallVector NewRanges; // Check all basic blocks for live-ins. for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end(); @@ -280,23 +287,25 @@ void LiveIntervals::computeLiveInRegUnits() { LIE = MBB->livein_end(); LII != LIE; ++LII) { for (MCRegUnitIterator Units(*LII, TRI); Units.isValid(); ++Units) { unsigned Unit = *Units; - LiveInterval *Intv = RegUnitIntervals[Unit]; - if (!Intv) { - Intv = RegUnitIntervals[Unit] = new LiveInterval(Unit, HUGE_VALF); - NewIntvs.push_back(Intv); + LiveRange *LR = RegUnitRanges[Unit]; + if (!LR) { + LR = RegUnitRanges[Unit] = new LiveRange(); + NewRanges.push_back(Unit); } - VNInfo *VNI = Intv->createDeadDef(Begin, getVNInfoAllocator()); + VNInfo *VNI = LR->createDeadDef(Begin, getVNInfoAllocator()); (void)VNI; DEBUG(dbgs() << ' ' << PrintRegUnit(Unit, TRI) << '#' << VNI->id); } } DEBUG(dbgs() << '\n'); } - DEBUG(dbgs() << "Created " << NewIntvs.size() << " new intervals.\n"); + DEBUG(dbgs() << "Created " << NewRanges.size() << " new intervals.\n"); - // Compute the 'normal' part of the intervals. - for (unsigned i = 0, e = NewIntvs.size(); i != e; ++i) - computeRegUnitInterval(NewIntvs[i]); + // Compute the 'normal' part of the ranges. + for (unsigned i = 0, e = NewRanges.size(); i != e; ++i) { + unsigned Unit = NewRanges[i]; + computeRegUnitRange(*RegUnitRanges[Unit], Unit); + } } @@ -320,7 +329,7 @@ bool LiveIntervals::shrinkToUses(LiveInterval *li, if (UseMI->isDebugValue() || !UseMI->readsVirtualRegister(li->reg)) continue; SlotIndex Idx = getInstructionIndex(UseMI).getRegSlot(); - LiveRangeQuery LRQ(*li, Idx); + LiveQueryResult LRQ = li->Query(Idx); VNInfo *VNI = LRQ.valueIn(); if (!VNI) { // This shouldn't happen: readsVirtualRegister returns true, but there is @@ -339,14 +348,14 @@ bool LiveIntervals::shrinkToUses(LiveInterval *li, WorkList.push_back(std::make_pair(Idx, VNI)); } - // Create a new live interval with only minimal live segments per def. - LiveInterval NewLI(li->reg, 0); + // Create new live ranges with only minimal live segments per def. + LiveRange NewLR; for (LiveInterval::vni_iterator I = li->vni_begin(), E = li->vni_end(); I != E; ++I) { VNInfo *VNI = *I; if (VNI->isUnused()) continue; - NewLI.addRange(LiveRange(VNI->def, VNI->def.getDeadSlot(), VNI)); + NewLR.addSegment(LiveRange::Segment(VNI->def, VNI->def.getDeadSlot(), VNI)); } // Keep track of the PHIs that are in use. @@ -361,7 +370,7 @@ bool LiveIntervals::shrinkToUses(LiveInterval *li, SlotIndex BlockStart = getMBBStartIdx(MBB); // Extend the live range for VNI to be live at Idx. - if (VNInfo *ExtVNI = NewLI.extendInBlock(BlockStart, Idx)) { + if (VNInfo *ExtVNI = NewLR.extendInBlock(BlockStart, Idx)) { (void)ExtVNI; assert(ExtVNI == VNI && "Unexpected existing value number"); // Is this a PHIDef we haven't seen before? @@ -382,7 +391,7 @@ bool LiveIntervals::shrinkToUses(LiveInterval *li, // VNI is live-in to MBB. DEBUG(dbgs() << " live-in at " << BlockStart << '\n'); - NewLI.addRange(LiveRange(BlockStart, Idx, VNI)); + NewLR.addSegment(LiveRange::Segment(BlockStart, Idx, VNI)); // Make sure VNI is live-out from the predecessors. for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), @@ -403,14 +412,14 @@ bool LiveIntervals::shrinkToUses(LiveInterval *li, VNInfo *VNI = *I; if (VNI->isUnused()) continue; - LiveInterval::iterator LII = NewLI.FindLiveRangeContaining(VNI->def); - assert(LII != NewLI.end() && "Missing live range for PHI"); - if (LII->end != VNI->def.getDeadSlot()) + LiveRange::iterator LRI = NewLR.FindSegmentContaining(VNI->def); + assert(LRI != NewLR.end() && "Missing segment for PHI"); + if (LRI->end != VNI->def.getDeadSlot()) continue; if (VNI->isPHIDef()) { // This is a dead PHI. Remove it. VNI->markUnused(); - NewLI.removeRange(*LII); + NewLR.removeSegment(LRI->start, LRI->end); DEBUG(dbgs() << "Dead PHI at " << VNI->def << " may separate interval\n"); CanSeparate = true; } else { @@ -425,23 +434,23 @@ bool LiveIntervals::shrinkToUses(LiveInterval *li, } } - // Move the trimmed ranges back. - li->ranges.swap(NewLI.ranges); + // Move the trimmed segments back. + li->segments.swap(NewLR.segments); DEBUG(dbgs() << "Shrunk: " << *li << '\n'); return CanSeparate; } -void LiveIntervals::extendToIndices(LiveInterval *LI, +void LiveIntervals::extendToIndices(LiveRange &LR, ArrayRef Indices) { assert(LRCalc && "LRCalc not initialized."); LRCalc->reset(MF, getSlotIndexes(), DomTree, &getVNInfoAllocator()); for (unsigned i = 0, e = Indices.size(); i != e; ++i) - LRCalc->extend(LI, Indices[i]); + LRCalc->extend(LR, Indices[i]); } void LiveIntervals::pruneValue(LiveInterval *LI, SlotIndex Kill, SmallVectorImpl *EndPoints) { - LiveRangeQuery LRQ(*LI, Kill); + LiveQueryResult LRQ = LI->Query(Kill); VNInfo *VNI = LRQ.valueOut(); if (!VNI) return; @@ -452,13 +461,13 @@ void LiveIntervals::pruneValue(LiveInterval *LI, SlotIndex Kill, // If VNI isn't live out from KillMBB, the value is trivially pruned. if (LRQ.endPoint() < MBBEnd) { - LI->removeRange(Kill, LRQ.endPoint()); + LI->removeSegment(Kill, LRQ.endPoint()); if (EndPoints) EndPoints->push_back(LRQ.endPoint()); return; } // VNI is live out of KillMBB. - LI->removeRange(Kill, MBBEnd); + LI->removeSegment(Kill, MBBEnd); if (EndPoints) EndPoints->push_back(MBBEnd); // Find all blocks that are reachable from KillMBB without leaving VNI's live @@ -476,23 +485,23 @@ void LiveIntervals::pruneValue(LiveInterval *LI, SlotIndex Kill, // Check if VNI is live in to MBB. tie(MBBStart, MBBEnd) = Indexes->getMBBRange(MBB); - LiveRangeQuery LRQ(*LI, MBBStart); + LiveQueryResult LRQ = LI->Query(MBBStart); if (LRQ.valueIn() != VNI) { - // This block isn't part of the VNI live range. Prune the search. + // This block isn't part of the VNI segment. Prune the search. I.skipChildren(); continue; } // Prune the search if VNI is killed in MBB. if (LRQ.endPoint() < MBBEnd) { - LI->removeRange(MBBStart, LRQ.endPoint()); + LI->removeSegment(MBBStart, LRQ.endPoint()); if (EndPoints) EndPoints->push_back(LRQ.endPoint()); I.skipChildren(); continue; } // VNI is live through MBB. - LI->removeRange(MBBStart, MBBEnd); + LI->removeSegment(MBBStart, MBBEnd); if (EndPoints) EndPoints->push_back(MBBEnd); ++I; } @@ -505,7 +514,7 @@ void LiveIntervals::pruneValue(LiveInterval *LI, SlotIndex Kill, void LiveIntervals::addKillFlags(const VirtRegMap *VRM) { // Keep track of regunit ranges. - SmallVector, 8> RU; + SmallVector, 8> RU; for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) { unsigned Reg = TargetRegisterInfo::index2VirtReg(i); @@ -520,13 +529,14 @@ void LiveIntervals::addKillFlags(const VirtRegMap *VRM) { RU.clear(); for (MCRegUnitIterator Units(VRM->getPhys(Reg), TRI); Units.isValid(); ++Units) { - LiveInterval *RUInt = &getRegUnit(*Units); - if (RUInt->empty()) + LiveRange &RURanges = getRegUnit(*Units); + if (RURanges.empty()) continue; - RU.push_back(std::make_pair(RUInt, RUInt->find(LI->begin()->end))); + RU.push_back(std::make_pair(&RURanges, RURanges.find(LI->begin()->end))); } - // Every instruction that kills Reg corresponds to a live range end point. + // Every instruction that kills Reg corresponds to a segment range end + // point. for (LiveInterval::iterator RI = LI->begin(), RE = LI->end(); RI != RE; ++RI) { // A block index indicates an MBB edge. @@ -536,7 +546,7 @@ void LiveIntervals::addKillFlags(const VirtRegMap *VRM) { if (!MI) continue; - // Check if any of the reguints are live beyond the end of RI. That could + // Check if any of the regunits are live beyond the end of RI. That could // happen when a physreg is defined as a copy of a virtreg: // // %EAX = COPY %vreg5 @@ -546,12 +556,12 @@ void LiveIntervals::addKillFlags(const VirtRegMap *VRM) { // There should be no kill flag on FOO when %vreg5 is rewritten as %EAX. bool CancelKill = false; for (unsigned u = 0, e = RU.size(); u != e; ++u) { - LiveInterval *RInt = RU[u].first; - LiveInterval::iterator &I = RU[u].second; - if (I == RInt->end()) + LiveRange &RRanges = *RU[u].first; + LiveRange::iterator &I = RU[u].second; + if (I == RRanges.end()) continue; - I = RInt->advanceTo(I, RI->end); - if (I == RInt->end() || I->start >= RI->end) + I = RRanges.advanceTo(I, RI->end); + if (I == RRanges.end() || I->start >= RI->end) continue; // I is overlapping RI. CancelKill = true; @@ -609,35 +619,23 @@ LiveIntervals::hasPHIKill(const LiveInterval &LI, const VNInfo *VNI) const { } float -LiveIntervals::getSpillWeight(bool isDef, bool isUse, unsigned loopDepth) { - // Limit the loop depth ridiculousness. - if (loopDepth > 200) - loopDepth = 200; - - // The loop depth is used to roughly estimate the number of times the - // instruction is executed. Something like 10^d is simple, but will quickly - // overflow a float. This expression behaves like 10^d for small d, but is - // more tempered for large d. At d=200 we get 6.7e33 which leaves a bit of - // headroom before overflow. - // By the way, powf() might be unavailable here. For consistency, - // We may take pow(double,double). - float lc = std::pow(1 + (100.0 / (loopDepth + 10)), (double)loopDepth); - - return (isDef + isUse) * lc; +LiveIntervals::getSpillWeight(bool isDef, bool isUse, BlockFrequency freq) { + const float Scale = 1.0f / BlockFrequency::getEntryFrequency(); + return (isDef + isUse) * (freq.getFrequency() * Scale); } -LiveRange LiveIntervals::addLiveRangeToEndOfBlock(unsigned reg, - MachineInstr* startInst) { - LiveInterval& Interval = getOrCreateInterval(reg); +LiveRange::Segment +LiveIntervals::addSegmentToEndOfBlock(unsigned reg, MachineInstr* startInst) { + LiveInterval& Interval = createEmptyInterval(reg); VNInfo* VN = Interval.getNextValue( SlotIndex(getInstructionIndex(startInst).getRegSlot()), getVNInfoAllocator()); - LiveRange LR( + LiveRange::Segment S( SlotIndex(getInstructionIndex(startInst).getRegSlot()), getMBBEndIdx(startInst->getParent()), VN); - Interval.addRange(LR); + Interval.addSegment(S); - return LR; + return S; } @@ -712,7 +710,7 @@ private: const TargetRegisterInfo& TRI; SlotIndex OldIdx; SlotIndex NewIdx; - SmallPtrSet Updated; + SmallPtrSet Updated; bool UpdateFlags; public: @@ -726,7 +724,7 @@ public: // physregs, even those that aren't needed for regalloc, in order to update // kill flags. This is wasteful. Eventually, LiveVariables will strip all kill // flags, and postRA passes will use a live register utility instead. - LiveInterval *getRegUnitLI(unsigned Unit) { + LiveRange *getRegUnitLI(unsigned Unit) { if (UpdateFlags) return &LIS.getRegUnit(Unit); return LIS.getCachedRegUnit(Unit); @@ -751,15 +749,16 @@ public: if (!Reg) continue; if (TargetRegisterInfo::isVirtualRegister(Reg)) { - updateRange(LIS.getInterval(Reg)); + LiveInterval &LI = LIS.getInterval(Reg); + updateRange(LI, Reg); continue; } // For physregs, only update the regunits that actually have a // precomputed live range. for (MCRegUnitIterator Units(Reg, &TRI); Units.isValid(); ++Units) - if (LiveInterval *LI = getRegUnitLI(*Units)) - updateRange(*LI); + if (LiveRange *LR = getRegUnitLI(*Units)) + updateRange(*LR, *Units); } if (hasRegMask) updateRegMaskSlots(); @@ -768,26 +767,26 @@ public: private: /// Update a single live range, assuming an instruction has been moved from /// OldIdx to NewIdx. - void updateRange(LiveInterval &LI) { - if (!Updated.insert(&LI)) + void updateRange(LiveRange &LR, unsigned Reg) { + if (!Updated.insert(&LR)) return; DEBUG({ dbgs() << " "; - if (TargetRegisterInfo::isVirtualRegister(LI.reg)) - dbgs() << PrintReg(LI.reg); + if (TargetRegisterInfo::isVirtualRegister(Reg)) + dbgs() << PrintReg(Reg); else - dbgs() << PrintRegUnit(LI.reg, &TRI); - dbgs() << ":\t" << LI << '\n'; + dbgs() << PrintRegUnit(Reg, &TRI); + dbgs() << ":\t" << LR << '\n'; }); if (SlotIndex::isEarlierInstr(OldIdx, NewIdx)) - handleMoveDown(LI); + handleMoveDown(LR); else - handleMoveUp(LI); - DEBUG(dbgs() << " -->\t" << LI << '\n'); - LI.verify(); + handleMoveUp(LR, Reg); + DEBUG(dbgs() << " -->\t" << LR << '\n'); + LR.verify(); } - /// Update LI to reflect an instruction has been moved downwards from OldIdx + /// Update LR to reflect an instruction has been moved downwards from OldIdx /// to NewIdx. /// /// 1. Live def at OldIdx: @@ -801,17 +800,17 @@ private: /// Move def to NewIdx, possibly across another live value. /// /// 4. Def at OldIdx AND at NewIdx: - /// Remove live range [OldIdx;NewIdx) and value defined at OldIdx. + /// Remove segment [OldIdx;NewIdx) and value defined at OldIdx. /// (Happens when bundling multiple defs together). /// /// 5. Value read at OldIdx, killed before NewIdx: /// Extend kill to NewIdx. /// - void handleMoveDown(LiveInterval &LI) { + void handleMoveDown(LiveRange &LR) { // First look for a kill at OldIdx. - LiveInterval::iterator I = LI.find(OldIdx.getBaseIndex()); - LiveInterval::iterator E = LI.end(); - // Is LI even live at OldIdx? + LiveRange::iterator I = LR.find(OldIdx.getBaseIndex()); + LiveRange::iterator E = LR.end(); + // Is LR even live at OldIdx? if (I == E || SlotIndex::isEarlierInstr(OldIdx, I->start)) return; @@ -828,7 +827,7 @@ private: for (MIBundleOperands MO(KillMI); MO.isValid(); ++MO) if (MO->isReg() && MO->isUse()) MO->setIsKill(false); - // Adjust I->end to reach NewIdx. This may temporarily make LI invalid by + // Adjust I->end to reach NewIdx. This may temporarily make LR invalid by // overlapping ranges. Case 5 above. I->end = NewIdx.getRegSlot(I->end.isEarlyClobber()); // If this was a kill, there may also be a def. Otherwise we're done. @@ -857,24 +856,25 @@ private: assert((I->end == OldIdx.getDeadSlot() || SlotIndex::isSameInstr(I->end, NewIdx)) && "Cannot move def below kill"); - LiveInterval::iterator NewI = LI.advanceTo(I, NewIdx.getRegSlot()); + LiveRange::iterator NewI = LR.advanceTo(I, NewIdx.getRegSlot()); if (NewI != E && SlotIndex::isSameInstr(NewI->start, NewIdx)) { // There is an existing def at NewIdx, case 4 above. The def at OldIdx is // coalesced into that value. assert(NewI->valno != DefVNI && "Multiple defs of value?"); - LI.removeValNo(DefVNI); + LR.removeValNo(DefVNI); return; } // There was no existing def at NewIdx. Turn *I into a dead def at NewIdx. - // If the def at OldIdx was dead, we allow it to be moved across other LI + // If the def at OldIdx was dead, we allow it to be moved across other LR // values. The new range should be placed immediately before NewI, move any // intermediate ranges up. assert(NewI != I && "Inconsistent iterators"); std::copy(llvm::next(I), NewI, I); - *llvm::prior(NewI) = LiveRange(DefVNI->def, NewIdx.getDeadSlot(), DefVNI); + *llvm::prior(NewI) + = LiveRange::Segment(DefVNI->def, NewIdx.getDeadSlot(), DefVNI); } - /// Update LI to reflect an instruction has been moved upwards from OldIdx + /// Update LR to reflect an instruction has been moved upwards from OldIdx /// to NewIdx. /// /// 1. Live def at OldIdx: @@ -894,11 +894,11 @@ private: /// Hoist kill to NewIdx, then scan for last kill between NewIdx and /// OldIdx. /// - void handleMoveUp(LiveInterval &LI) { + void handleMoveUp(LiveRange &LR, unsigned Reg) { // First look for a kill at OldIdx. - LiveInterval::iterator I = LI.find(OldIdx.getBaseIndex()); - LiveInterval::iterator E = LI.end(); - // Is LI even live at OldIdx? + LiveRange::iterator I = LR.find(OldIdx.getBaseIndex()); + LiveRange::iterator E = LR.end(); + // Is LR even live at OldIdx? if (I == E || SlotIndex::isEarlierInstr(OldIdx, I->start)) return; @@ -915,7 +915,7 @@ private: if (I == E || !SlotIndex::isSameInstr(I->start, OldIdx)) { // No def, search for the new kill. // This can never be an early clobber kill since there is no def. - llvm::prior(I)->end = findLastUseBefore(LI.reg).getRegSlot(); + llvm::prior(I)->end = findLastUseBefore(Reg).getRegSlot(); return; } } @@ -927,18 +927,18 @@ private: DefVNI->def = NewIdx.getRegSlot(I->start.isEarlyClobber()); // Check for an existing def at NewIdx. - LiveInterval::iterator NewI = LI.find(NewIdx.getRegSlot()); + LiveRange::iterator NewI = LR.find(NewIdx.getRegSlot()); if (SlotIndex::isSameInstr(NewI->start, NewIdx)) { assert(NewI->valno != DefVNI && "Same value defined more than once?"); // There is an existing def at NewIdx. if (I->end.isDead()) { // Case 3: Remove the dead def at OldIdx. - LI.removeValNo(DefVNI); + LR.removeValNo(DefVNI); return; } // Case 4: Replace def at NewIdx with live def at OldIdx. I->start = DefVNI->def; - LI.removeValNo(NewI->valno); + LR.removeValNo(NewI->valno); return; } @@ -949,10 +949,10 @@ private: return; } - // DefVNI is a dead def. It may have been moved across other values in LI, + // DefVNI is a dead def. It may have been moved across other values in LR, // so move I up to NewI. Slide [NewI;I) down one position. std::copy_backward(NewI, I, llvm::next(I)); - *NewI = LiveRange(DefVNI->def, NewIdx.getDeadSlot(), DefVNI); + *NewI = LiveRange::Segment(DefVNI->def, NewIdx.getDeadSlot(), DefVNI); } void updateRegMaskSlots() { @@ -972,9 +972,9 @@ private: // Return the last use of reg between NewIdx and OldIdx. SlotIndex findLastUseBefore(unsigned Reg) { - SlotIndex LastUse = NewIdx; if (TargetRegisterInfo::isVirtualRegister(Reg)) { + SlotIndex LastUse = NewIdx; for (MachineRegisterInfo::use_nodbg_iterator UI = MRI.use_nodbg_begin(Reg), UE = MRI.use_nodbg_end(); @@ -984,30 +984,42 @@ private: if (InstSlot > LastUse && InstSlot < OldIdx) LastUse = InstSlot; } - } else { - MachineInstr* MI = LIS.getSlotIndexes()->getInstructionFromIndex(NewIdx); - MachineBasicBlock::iterator MII(MI); - ++MII; - MachineBasicBlock* MBB = MI->getParent(); - for (; MII != MBB->end(); ++MII){ - if (MII->isDebugValue()) - continue; - if (LIS.getInstructionIndex(MII) < OldIdx) - break; - for (MachineInstr::mop_iterator MOI = MII->operands_begin(), - MOE = MII->operands_end(); - MOI != MOE; ++MOI) { - const MachineOperand& mop = *MOI; - if (!mop.isReg() || mop.getReg() == 0 || - TargetRegisterInfo::isVirtualRegister(mop.getReg())) - continue; - - if (TRI.hasRegUnit(mop.getReg(), Reg)) - LastUse = LIS.getInstructionIndex(MII); - } - } + return LastUse; + } + + // This is a regunit interval, so scanning the use list could be very + // expensive. Scan upwards from OldIdx instead. + assert(NewIdx < OldIdx && "Expected upwards move"); + SlotIndexes *Indexes = LIS.getSlotIndexes(); + MachineBasicBlock *MBB = Indexes->getMBBFromIndex(NewIdx); + + // OldIdx may not correspond to an instruction any longer, so set MII to + // point to the next instruction after OldIdx, or MBB->end(). + MachineBasicBlock::iterator MII = MBB->end(); + if (MachineInstr *MI = Indexes->getInstructionFromIndex( + Indexes->getNextNonNullIndex(OldIdx))) + if (MI->getParent() == MBB) + MII = MI; + + MachineBasicBlock::iterator Begin = MBB->begin(); + while (MII != Begin) { + if ((--MII)->isDebugValue()) + continue; + SlotIndex Idx = Indexes->getInstructionIndex(MII); + + // Stop searching when NewIdx is reached. + if (!SlotIndex::isEarlierInstr(NewIdx, Idx)) + return NewIdx; + + // Check if MII uses Reg. + for (MIBundleOperands MO(MII); MO.isValid(); ++MO) + if (MO->isReg() && + TargetRegisterInfo::isPhysicalRegister(MO->getReg()) && + TRI.hasRegUnit(MO->getReg(), Reg)) + return Idx; } - return LastUse; + // Didn't reach NewIdx. It must be the first instruction in the block. + return NewIdx; } }; @@ -1038,6 +1050,13 @@ LiveIntervals::repairIntervalsInRange(MachineBasicBlock *MBB, MachineBasicBlock::iterator Begin, MachineBasicBlock::iterator End, ArrayRef OrigRegs) { + // Find anchor points, which are at the beginning/end of blocks or at + // instructions that already have indexes. + while (Begin != MBB->begin() && !Indexes->hasIndex(Begin)) + --Begin; + while (End != MBB->end() && !Indexes->hasIndex(End)) + ++End; + SlotIndex endIdx; if (End == MBB->end()) endIdx = getMBBEndIdx(MBB).getPrevSlot(); @@ -1049,13 +1068,14 @@ LiveIntervals::repairIntervalsInRange(MachineBasicBlock *MBB, for (MachineBasicBlock::iterator I = End; I != Begin;) { --I; MachineInstr *MI = I; + if (MI->isDebugValue()) + continue; for (MachineInstr::const_mop_iterator MOI = MI->operands_begin(), MOE = MI->operands_end(); MOI != MOE; ++MOI) { if (MOI->isReg() && TargetRegisterInfo::isVirtualRegister(MOI->getReg()) && !hasInterval(MOI->getReg())) { - LiveInterval &LI = getOrCreateInterval(MOI->getReg()); - computeVirtRegInterval(&LI); + createAndComputeVirtRegInterval(MOI->getReg()); } } } @@ -1066,13 +1086,29 @@ LiveIntervals::repairIntervalsInRange(MachineBasicBlock *MBB, continue; LiveInterval &LI = getInterval(Reg); - LiveInterval::iterator LII = LI.FindLiveRangeContaining(endIdx); + // FIXME: Should we support undefs that gain defs? + if (!LI.hasAtLeastOneValue()) + continue; + + LiveInterval::iterator LII = LI.find(endIdx); + SlotIndex lastUseIdx; + if (LII != LI.end() && LII->start < endIdx) + lastUseIdx = LII->end; + else + --LII; for (MachineBasicBlock::iterator I = End; I != Begin;) { --I; MachineInstr *MI = I; + if (MI->isDebugValue()) + continue; + SlotIndex instrIdx = getInstructionIndex(MI); + bool isStartValid = getInstructionFromIndex(LII->start); + bool isEndValid = getInstructionFromIndex(LII->end); + // FIXME: This doesn't currently handle early-clobber or multiple removed + // defs inside of the region to repair. for (MachineInstr::mop_iterator OI = MI->operands_begin(), OE = MI->operands_end(); OI != OE; ++OI) { const MachineOperand &MO = *OI; @@ -1080,25 +1116,55 @@ LiveIntervals::repairIntervalsInRange(MachineBasicBlock *MBB, continue; if (MO.isDef()) { - assert(LII != LI.end() && - "Dead register defs are not yet supported."); - if (!Indexes->getInstructionFromIndex(LII->start)) { - LII->start = instrIdx.getRegSlot(); - LII->valno->def = instrIdx.getRegSlot(); + if (!isStartValid) { + if (LII->end.isDead()) { + SlotIndex prevStart; + if (LII != LI.begin()) + prevStart = llvm::prior(LII)->start; + + // FIXME: This could be more efficient if there was a + // removeSegment method that returned an iterator. + LI.removeSegment(*LII, true); + if (prevStart.isValid()) + LII = LI.find(prevStart); + else + LII = LI.begin(); + } else { + LII->start = instrIdx.getRegSlot(); + LII->valno->def = instrIdx.getRegSlot(); + if (MO.getSubReg() && !MO.isUndef()) + lastUseIdx = instrIdx.getRegSlot(); + else + lastUseIdx = SlotIndex(); + continue; + } + } + + if (!lastUseIdx.isValid()) { + VNInfo *VNI = LI.getNextValue(instrIdx.getRegSlot(), + VNInfoAllocator); + LiveRange::Segment S(instrIdx.getRegSlot(), + instrIdx.getDeadSlot(), VNI); + LII = LI.addSegment(S); } else if (LII->start != instrIdx.getRegSlot()) { - VNInfo *VNI = LI.getNextValue(instrIdx.getRegSlot(), VNInfoAllocator); - LiveRange LR = LiveRange(instrIdx.getRegSlot(), LII->start, VNI); - LII = LI.addRange(LR); + VNInfo *VNI = LI.getNextValue(instrIdx.getRegSlot(), + VNInfoAllocator); + LiveRange::Segment S(instrIdx.getRegSlot(), lastUseIdx, VNI); + LII = LI.addSegment(S); } - } else if (MO.isUse()) { - if (LII == LI.end()) - --LII; - assert(LII->start < instrIdx && - "Registers with multiple used live ranges are not yet supported."); - SlotIndex endIdx = LII->end; - if (!endIdx.isBlock() && !Indexes->getInstructionFromIndex(endIdx)) + if (MO.getSubReg() && !MO.isUndef()) + lastUseIdx = instrIdx.getRegSlot(); + else + lastUseIdx = SlotIndex(); + } else if (MO.isUse()) { + // FIXME: This should probably be handled outside of this branch, + // either as part of the def case (for defs inside of the region) or + // after the loop over the region. + if (!isEndValid && !LII->end.isBlock()) LII->end = instrIdx.getRegSlot(); + if (!lastUseIdx.isValid()) + lastUseIdx = instrIdx.getRegSlot(); } } }