X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FLiveIntervalAnalysis.cpp;h=83df4d174a4cb0b0b5129fd8fa0dac2c1085a577;hb=3627e34486db088661bc7fb6c0dde6a18a543217;hp=80d3547e4b41798b68e8d3d19bbdad5d7d0a44a0;hpb=749c6f6b5ed301c84aac562e414486549d7b98eb;p=oota-llvm.git diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp index 80d3547e4b4..83df4d174a4 100644 --- a/lib/CodeGen/LiveIntervalAnalysis.cpp +++ b/lib/CodeGen/LiveIntervalAnalysis.cpp @@ -25,7 +25,7 @@ #include "llvm/CodeGen/MachineLoopInfo.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/CodeGen/Passes.h" -#include "llvm/Target/MRegisterInfo.h" +#include "llvm/Target/TargetRegisterInfo.h" #include "llvm/Target/TargetInstrInfo.h" #include "llvm/Target/TargetMachine.h" #include "llvm/Support/CommandLine.h" @@ -36,16 +36,14 @@ #include using namespace llvm; -namespace { - // Hidden options for help debugging. - cl::opt DisableReMat("disable-rematerialization", - cl::init(false), cl::Hidden); - - cl::opt SplitAtBB("split-intervals-at-bb", - cl::init(true), cl::Hidden); - cl::opt SplitLimit("split-limit", - cl::init(-1), cl::Hidden); -} +// Hidden options for help debugging. +static cl::opt DisableReMat("disable-rematerialization", + cl::init(false), cl::Hidden); + +static cl::opt SplitAtBB("split-intervals-at-bb", + cl::init(true), cl::Hidden); +static cl::opt SplitLimit("split-limit", + cl::init(-1), cl::Hidden); STATISTIC(numIntervals, "Number of original intervals"); STATISTIC(numIntervalsAfter, "Number of intervals after coalescing"); @@ -53,9 +51,7 @@ STATISTIC(numFolds , "Number of loads/stores folded into instructions"); STATISTIC(numSplits , "Number of intervals split"); char LiveIntervals::ID = 0; -namespace { - RegisterPass X("liveintervals", "Live Interval Analysis"); -} +static RegisterPass X("liveintervals", "Live Interval Analysis"); void LiveIntervals::getAnalysisUsage(AnalysisUsage &AU) const { AU.addPreserved(); @@ -69,6 +65,7 @@ void LiveIntervals::getAnalysisUsage(AnalysisUsage &AU) const { } void LiveIntervals::releaseMemory() { + MBB2IdxMap.clear(); Idx2MBBMap.clear(); mi2iMap_.clear(); i2miMap_.clear(); @@ -79,32 +76,14 @@ void LiveIntervals::releaseMemory() { delete ClonedMIs[i]; } -namespace llvm { - inline bool operator<(unsigned V, const IdxMBBPair &IM) { - return V < IM.first; - } - - inline bool operator<(const IdxMBBPair &IM, unsigned V) { - return IM.first < V; - } - - struct Idx2MBBCompare { - bool operator()(const IdxMBBPair &LHS, const IdxMBBPair &RHS) const { - return LHS.first < RHS.first; - } - }; -} - -/// runOnMachineFunction - Register allocate the whole function -/// -bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) { - mf_ = &fn; - tm_ = &fn.getTarget(); - mri_ = tm_->getRegisterInfo(); - tii_ = tm_->getInstrInfo(); - lv_ = &getAnalysis(); - allocatableRegs_ = mri_->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)); @@ -121,20 +100,127 @@ bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) { 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()] = 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(); + allocatableRegs_ = tri_->getAllocatableSet(fn); + computeNumbering(); computeIntervals(); numIntervals += getNumIntervals(); DOUT << "********** INTERVALS **********\n"; for (iterator I = begin(), E = end(); I != E; ++I) { - I->second.print(DOUT, mri_); + I->second.print(DOUT, tri_); DOUT << "\n"; } @@ -147,8 +233,8 @@ bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) { 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, mri_); - DOUT << "\n"; + I->second.print(O, tri_); + O << "\n"; } O << "********** MACHINEINSTRS **********\n"; @@ -188,12 +274,12 @@ bool LiveIntervals::conflictsWithPhysRegDef(const LiveInterval &li, unsigned PhysReg = mop.getReg(); if (PhysReg == 0 || PhysReg == li.reg) continue; - if (MRegisterInfo::isVirtualRegister(PhysReg)) { + if (TargetRegisterInfo::isVirtualRegister(PhysReg)) { if (!vrm.hasPhys(PhysReg)) continue; PhysReg = vrm.getPhys(PhysReg); } - if (PhysReg && mri_->regsOverlap(PhysReg, reg)) + if (PhysReg && tri_->regsOverlap(PhysReg, reg)) return true; } } @@ -203,8 +289,8 @@ bool LiveIntervals::conflictsWithPhysRegDef(const LiveInterval &li, } void LiveIntervals::printRegName(unsigned reg) const { - if (MRegisterInfo::isPhysicalRegister(reg)) - cerr << mri_->getName(reg); + if (TargetRegisterInfo::isPhysicalRegister(reg)) + cerr << tri_->getName(reg); else cerr << "%reg" << reg; } @@ -216,6 +302,11 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb, DOUT << "\t\tregister: "; DEBUG(printRegName(interval.reg)); LiveVariables::VarInfo& vi = lv_->getVarInfo(interval.reg); + if (mi->getOpcode() == TargetInstrInfo::IMPLICIT_DEF) { + DOUT << "is a implicit_def\n"; + return; + } + // Virtual registers may be defined multiple times (due to phi // elimination and 2-addr elimination). Much of what we do only has to be // done once for the vreg. We use an empty interval to detect the first @@ -224,14 +315,13 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb, // Get the Idx of the defining instructions. unsigned defIndex = getDefIndex(MIIdx); VNInfo *ValNo; + MachineInstr *CopyMI = NULL; unsigned SrcReg, DstReg; - if (tii_->isMoveInstr(*mi, SrcReg, DstReg)) - ValNo = interval.getNextValue(defIndex, SrcReg, VNInfoAllocator); - else if (mi->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) - ValNo = interval.getNextValue(defIndex, mi->getOperand(1).getReg(), - VNInfoAllocator); - else - ValNo = interval.getNextValue(defIndex, 0, VNInfoAllocator); + if (mi->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG || + mi->getOpcode() == TargetInstrInfo::INSERT_SUBREG || + tii_->isMoveInstr(*mi, SrcReg, DstReg)) + CopyMI = mi; + ValNo = interval.getNextValue(defIndex, CopyMI, VNInfoAllocator); assert(ValNo->id == 0 && "First value in interval is not 0?"); @@ -275,14 +365,11 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb, // 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; } } @@ -309,12 +396,12 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb, // are actually two values in the live interval. Because of this we // need to take the LiveRegion that defines this register and split it // into two values. - unsigned DefIndex = getDefIndex(getInstructionIndex(vi.DefInst)); + assert(interval.containsOneValue()); + unsigned DefIndex = getDefIndex(interval.getValNumInfo(0)->def); unsigned RedefIndex = getDefIndex(MIIdx); const LiveRange *OldLR = interval.getLiveRangeContaining(RedefIndex-1); VNInfo *OldValNo = OldLR->valno; - unsigned OldEnd = OldLR->end; // Delete the initial value, which should be short and continuous, // because the 2-addr copy must be in the same MBB as the redef. @@ -326,27 +413,26 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb, // The new value number (#1) is defined by the instruction we claimed // defined value #0. - VNInfo *ValNo = interval.getNextValue(0, 0, VNInfoAllocator); - interval.copyValNumInfo(ValNo, OldValNo); + VNInfo *ValNo = interval.getNextValue(OldValNo->def, OldValNo->copy, + VNInfoAllocator); // Value#0 is now defined by the 2-addr instruction. - OldValNo->def = RedefIndex; - OldValNo->reg = 0; + OldValNo->def = RedefIndex; + OldValNo->copy = 0; // Add the new live interval which replaces the range for the input copy. LiveRange LR(DefIndex, RedefIndex, ValNo); DOUT << " replace range with " << LR; interval.addRange(LR); interval.addKill(ValNo, RedefIndex); - interval.removeKills(ValNo, RedefIndex, OldEnd); // If this redefinition is dead, we need to add a dummy unit live // range covering the def slot. - if (lv_->RegisterDefIsDead(mi, interval.reg)) + if (mi->registerDefIsDead(interval.reg, tri_)) interval.addRange(LiveRange(RedefIndex, RedefIndex+1, OldValNo)); DOUT << " RESULT: "; - interval.print(DOUT, mri_); + interval.print(DOUT, tri_); } else { // Otherwise, this must be because of phi elimination. If this is the @@ -362,11 +448,10 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb, unsigned Start = getMBBStartIdx(Killer->getParent()); unsigned End = getUseIndex(getInstructionIndex(Killer))+1; DOUT << " Removing [" << Start << "," << End << "] from: "; - interval.print(DOUT, mri_); DOUT << "\n"; + interval.print(DOUT, tri_); DOUT << "\n"; interval.removeRange(Start, End); - interval.addKill(VNI, Start); VNI->hasPHIKill = true; - DOUT << " RESULT: "; interval.print(DOUT, mri_); + DOUT << " RESULT: "; interval.print(DOUT, tri_); // Replace the interval with one of a NEW value number. Note that this // value number isn't actually defined by an instruction, weird huh? :) @@ -374,7 +459,7 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb, DOUT << " replace range with " << LR; interval.addRange(LR); interval.addKill(LR.valno, End); - DOUT << " RESULT: "; interval.print(DOUT, mri_); + DOUT << " RESULT: "; interval.print(DOUT, tri_); } // In the case of PHI elimination, each variable definition is only @@ -383,14 +468,13 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb, unsigned defIndex = getDefIndex(MIIdx); VNInfo *ValNo; + MachineInstr *CopyMI = NULL; unsigned SrcReg, DstReg; - if (tii_->isMoveInstr(*mi, SrcReg, DstReg)) - ValNo = interval.getNextValue(defIndex, SrcReg, VNInfoAllocator); - else if (mi->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) - ValNo = interval.getNextValue(defIndex, mi->getOperand(1).getReg(), - VNInfoAllocator); - else - ValNo = interval.getNextValue(defIndex, 0, VNInfoAllocator); + if (mi->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG || + mi->getOpcode() == TargetInstrInfo::INSERT_SUBREG || + tii_->isMoveInstr(*mi, SrcReg, DstReg)) + CopyMI = mi; + ValNo = interval.getNextValue(defIndex, CopyMI, VNInfoAllocator); unsigned killIndex = getInstructionIndex(&mbb->back()) + InstrSlots::NUM; LiveRange LR(defIndex, killIndex, ValNo); @@ -408,7 +492,7 @@ void LiveIntervals::handlePhysicalRegisterDef(MachineBasicBlock *MBB, MachineBasicBlock::iterator mi, unsigned MIIdx, LiveInterval &interval, - unsigned SrcReg) { + MachineInstr *CopyMI) { // A physical register cannot be live across basic block, so its // lifetime must end somewhere in its defining basic block. DOUT << "\t\tregister: "; DEBUG(printRegName(interval.reg)); @@ -420,7 +504,7 @@ void LiveIntervals::handlePhysicalRegisterDef(MachineBasicBlock *MBB, // If it is not used after definition, it is considered dead at // the instruction defining it. Hence its interval is: // [defSlot(def), defSlot(def)+1) - if (lv_->RegisterDefIsDead(mi, interval.reg)) { + if (mi->registerDefIsDead(interval.reg, tri_)) { DOUT << " dead"; end = getDefIndex(start) + 1; goto exit; @@ -431,11 +515,11 @@ void LiveIntervals::handlePhysicalRegisterDef(MachineBasicBlock *MBB, // [defSlot(def), useSlot(kill)+1) while (++mi != MBB->end()) { baseIndex += InstrSlots::NUM; - if (lv_->KillsRegister(mi, interval.reg)) { + if (mi->killsRegister(interval.reg, tri_)) { DOUT << " killed"; end = getUseIndex(baseIndex) + 1; goto exit; - } else if (lv_->ModifiesRegister(mi, interval.reg)) { + } else if (mi->modifiesRegister(interval.reg, tri_)) { // Another instruction redefines the register before it is ever read. // Then the register is essentially dead at the instruction that defines // it. Hence its interval is: @@ -449,7 +533,7 @@ void LiveIntervals::handlePhysicalRegisterDef(MachineBasicBlock *MBB, // The only case we should have a dead physreg here without a killing or // instruction where we know it's dead is if it is live-in to the function // and never used. - assert(!SrcReg && "physreg was not killed in defining block!"); + assert(!CopyMI && "physreg was not killed in defining block!"); end = getDefIndex(start) + 1; // It's dead. exit: @@ -458,7 +542,7 @@ exit: // Already exists? Extend old live interval. LiveInterval::iterator OldLR = interval.FindLiveRangeContaining(start); VNInfo *ValNo = (OldLR != interval.end()) - ? OldLR->valno : interval.getNextValue(start, SrcReg, VNInfoAllocator); + ? OldLR->valno : interval.getNextValue(start, CopyMI, VNInfoAllocator); LiveRange LR(start, end, ValNo); interval.addRange(LR); interval.addKill(LR.valno, end); @@ -469,19 +553,21 @@ void LiveIntervals::handleRegisterDef(MachineBasicBlock *MBB, MachineBasicBlock::iterator MI, unsigned MIIdx, unsigned reg) { - if (MRegisterInfo::isVirtualRegister(reg)) + if (TargetRegisterInfo::isVirtualRegister(reg)) handleVirtualRegisterDef(MBB, MI, MIIdx, getOrCreateInterval(reg)); else if (allocatableRegs_[reg]) { + MachineInstr *CopyMI = NULL; unsigned SrcReg, DstReg; - if (MI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) - SrcReg = MI->getOperand(1).getReg(); - else if (!tii_->isMoveInstr(*MI, SrcReg, DstReg)) - SrcReg = 0; - handlePhysicalRegisterDef(MBB, MI, MIIdx, getOrCreateInterval(reg), SrcReg); + if (MI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG || + MI->getOpcode() == TargetInstrInfo::INSERT_SUBREG || + tii_->isMoveInstr(*MI, SrcReg, DstReg)) + CopyMI = MI; + handlePhysicalRegisterDef(MBB, MI, MIIdx, getOrCreateInterval(reg), CopyMI); // Def of a register also defines its sub-registers. - for (const unsigned* AS = mri_->getSubRegisters(reg); *AS; ++AS) - // Avoid processing some defs more than once. - if (!MI->findRegisterDefOperand(*AS)) + for (const unsigned* AS = tri_->getSubRegisters(reg); *AS; ++AS) + // If MI also modifies the sub-register explicitly, avoid processing it + // more than once. Do not pass in TRI here so it checks for exact match. + if (!MI->modifiesRegister(*AS)) handlePhysicalRegisterDef(MBB, MI, MIIdx, getOrCreateInterval(*AS), 0); } } @@ -498,11 +584,11 @@ void LiveIntervals::handleLiveInRegister(MachineBasicBlock *MBB, unsigned start = baseIndex; unsigned end = start; while (mi != MBB->end()) { - if (lv_->KillsRegister(mi, interval.reg)) { + if (mi->killsRegister(interval.reg, tri_)) { DOUT << " killed"; end = getUseIndex(baseIndex) + 1; goto exit; - } else if (lv_->ModifiesRegister(mi, interval.reg)) { + } else if (mi->modifiesRegister(interval.reg, tri_)) { // Another instruction redefines the register before it is ever read. // Then the register is essentially dead at the instruction that defines // it. Hence its interval is: @@ -556,7 +642,7 @@ void LiveIntervals::computeIntervals() { LE = MBB->livein_end(); LI != LE; ++LI) { handleLiveInRegister(MBB, MIIndex, getOrCreateInterval(*LI)); // Multiple live-ins can alias the same register. - for (const unsigned* AS = mri_->getSubRegisters(*LI); *AS; ++AS) + for (const unsigned* AS = tri_->getSubRegisters(*LI); *AS; ++AS) if (!hasInterval(*AS)) handleLiveInRegister(MBB, MIIndex, getOrCreateInterval(*AS), true); @@ -575,6 +661,8 @@ void LiveIntervals::computeIntervals() { MIIndex += InstrSlots::NUM; } + + if (MBB->begin() == miEnd) MIIndex += InstrSlots::NUM; // Empty MBB } } @@ -596,16 +684,64 @@ bool LiveIntervals::findLiveInMBBs(const LiveRange &LR, LiveInterval LiveIntervals::createInterval(unsigned reg) { - float Weight = MRegisterInfo::isPhysicalRegister(reg) ? + float Weight = TargetRegisterInfo::isPhysicalRegister(reg) ? HUGE_VALF : 0.0F; return LiveInterval(reg, Weight); } +/// getVNInfoSourceReg - Helper function that parses the specified VNInfo +/// copy field and returns the source register that defines it. +unsigned LiveIntervals::getVNInfoSourceReg(const VNInfo *VNI) const { + if (!VNI->copy) + return 0; + + if (VNI->copy->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) + return VNI->copy->getOperand(1).getReg(); + if (VNI->copy->getOpcode() == TargetInstrInfo::INSERT_SUBREG) + return VNI->copy->getOperand(2).getReg(); + unsigned SrcReg, DstReg; + if (tii_->isMoveInstr(*VNI->copy, SrcReg, DstReg)) + return SrcReg; + assert(0 && "Unrecognized copy instruction!"); + return 0; +} //===----------------------------------------------------------------------===// // Register allocator hooks. // +/// getReMatImplicitUse - If the remat definition MI has one (for now, we only +/// allow one) virtual register operand, then its uses are implicitly using +/// the register. Returns the virtual register. +unsigned LiveIntervals::getReMatImplicitUse(const LiveInterval &li, + MachineInstr *MI) const { + unsigned RegOp = 0; + for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { + MachineOperand &MO = MI->getOperand(i); + if (!MO.isRegister() || !MO.isUse()) + continue; + unsigned Reg = MO.getReg(); + if (Reg == 0 || Reg == li.reg) + continue; + // FIXME: For now, only remat MI with at most one register operand. + assert(!RegOp && + "Can't rematerialize instruction with multiple register operand!"); + RegOp = MO.getReg(); + break; + } + return RegOp; +} + +/// isValNoAvailableAt - Return true if the val# of the specified interval +/// which reaches the given instruction also reaches the specified use index. +bool LiveIntervals::isValNoAvailableAt(const LiveInterval &li, MachineInstr *MI, + unsigned UseIdx) const { + unsigned Index = getInstructionIndex(MI); + VNInfo *ValNo = li.FindLiveRangeContaining(Index)->valno; + LiveInterval::const_iterator UI = li.FindLiveRangeContaining(UseIdx); + return UI != li.end() && UI->valno == ValNo; +} + /// isReMaterializable - Returns true if the definition MI of the specified /// val# of the specified interval is re-materializable. bool LiveIntervals::isReMaterializable(const LiveInterval &li, @@ -615,36 +751,39 @@ bool LiveIntervals::isReMaterializable(const LiveInterval &li, return false; isLoad = false; - const TargetInstrDesc &TID = MI->getDesc(); - if (TID.isImplicitDef() || tii_->isTriviallyReMaterializable(MI)) { - isLoad = TID.isSimpleLoad(); + if (MI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF) return true; - } int FrameIdx = 0; - if (!tii_->isLoadFromStackSlot(MI, FrameIdx) || - !mf_->getFrameInfo()->isFixedObjectIndex(FrameIdx)) - return false; + if (tii_->isLoadFromStackSlot(MI, FrameIdx) && + mf_->getFrameInfo()->isImmutableObjectIndex(FrameIdx)) + // FIXME: Let target specific isReallyTriviallyReMaterializable determines + // this but remember this is not safe to fold into a two-address + // instruction. + // This is a load from fixed stack slot. It can be rematerialized. + return true; - // This is a load from fixed stack slot. It can be rematerialized unless it's - // re-defined by a two-address instruction. - isLoad = true; - for (LiveInterval::const_vni_iterator i = li.vni_begin(), e = li.vni_end(); - i != e; ++i) { - const VNInfo *VNI = *i; - if (VNI == ValNo) - continue; - unsigned DefIdx = VNI->def; - if (DefIdx == ~1U) - continue; // Dead val#. - MachineInstr *DefMI = (DefIdx == ~0u) - ? NULL : getInstructionFromIndex(DefIdx); - if (DefMI && DefMI->isRegReDefinedByTwoAddr(li.reg)) { - isLoad = false; - return false; + if (tii_->isTriviallyReMaterializable(MI)) { + const TargetInstrDesc &TID = MI->getDesc(); + isLoad = TID.isSimpleLoad(); + + unsigned ImpUse = getReMatImplicitUse(li, MI); + if (ImpUse) { + const LiveInterval &ImpLi = getInterval(ImpUse); + for (MachineRegisterInfo::use_iterator ri = mri_->use_begin(li.reg), + re = mri_->use_end(); ri != re; ++ri) { + MachineInstr *UseMI = &*ri; + unsigned UseIdx = getInstructionIndex(UseMI); + if (li.FindLiveRangeContaining(UseIdx)->valno != ValNo) + continue; + if (!isValNoAvailableAt(ImpLi, MI, UseIdx)) + return false; + } } + return true; } - return true; + + return false; } /// isReMaterializable - Returns true if every definition of MI of every @@ -662,13 +801,47 @@ bool LiveIntervals::isReMaterializable(const LiveInterval &li, bool &isLoad) { return false; MachineInstr *ReMatDefMI = getInstructionFromIndex(DefIdx); bool DefIsLoad = false; - if (!ReMatDefMI || !isReMaterializable(li, VNI, ReMatDefMI, DefIsLoad)) + if (!ReMatDefMI || + !isReMaterializable(li, VNI, ReMatDefMI, DefIsLoad)) return false; isLoad |= DefIsLoad; } return true; } +/// FilterFoldedOps - Filter out two-address use operands. Return +/// true if it finds any issue with the operands that ought to prevent +/// folding. +static bool FilterFoldedOps(MachineInstr *MI, + SmallVector &Ops, + unsigned &MRInfo, + SmallVector &FoldOps) { + const TargetInstrDesc &TID = MI->getDesc(); + + MRInfo = 0; + for (unsigned i = 0, e = Ops.size(); i != e; ++i) { + unsigned OpIdx = Ops[i]; + MachineOperand &MO = MI->getOperand(OpIdx); + // FIXME: fold subreg use. + if (MO.getSubReg()) + return true; + if (MO.isDef()) + MRInfo |= (unsigned)VirtRegMap::isMod; + else { + // Filter out two-address use operand(s). + if (!MO.isImplicit() && + TID.getOperandConstraint(OpIdx, TOI::TIED_TO) != -1) { + MRInfo = VirtRegMap::isModRef; + continue; + } + MRInfo |= (unsigned)VirtRegMap::isRef; + } + FoldOps.push_back(OpIdx); + } + return false; +} + + /// tryFoldMemoryOperand - Attempts to fold either a spill / restore from /// slot / to reg or any rematerialized load into ith operand of specified /// MI. If it is successul, MI is updated with the newly created MI and @@ -678,10 +851,8 @@ bool LiveIntervals::tryFoldMemoryOperand(MachineInstr* &MI, unsigned InstrIdx, SmallVector &Ops, bool isSS, int Slot, unsigned Reg) { - unsigned MRInfo = 0; - const TargetInstrDesc &TID = MI->getDesc(); // If it is an implicit def instruction, just delete it. - if (TID.isImplicitDef()) { + if (MI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF) { RemoveMachineInstrFromMaps(MI); vrm.RemoveMachineInstrFromMaps(MI); MI->eraseFromParent(); @@ -689,39 +860,36 @@ bool LiveIntervals::tryFoldMemoryOperand(MachineInstr* &MI, return true; } + // Filter the list of operand indexes that are to be folded. Abort if + // any operand will prevent folding. + unsigned MRInfo = 0; SmallVector FoldOps; - for (unsigned i = 0, e = Ops.size(); i != e; ++i) { - unsigned OpIdx = Ops[i]; - // FIXME: fold subreg use. - if (MI->getOperand(OpIdx).getSubReg()) - return false; - if (MI->getOperand(OpIdx).isDef()) - MRInfo |= (unsigned)VirtRegMap::isMod; - else { - // Filter out two-address use operand(s). - if (TID.getOperandConstraint(OpIdx, TOI::TIED_TO) != -1) { - MRInfo = VirtRegMap::isModRef; - continue; - } - MRInfo |= (unsigned)VirtRegMap::isRef; - } - FoldOps.push_back(OpIdx); - } + if (FilterFoldedOps(MI, Ops, MRInfo, FoldOps)) + return false; + + // The only time it's safe to fold into a two address instruction is when + // it's folding reload and spill from / into a spill stack slot. + if (DefMI && (MRInfo & VirtRegMap::isMod)) + return false; - MachineInstr *fmi = isSS ? tii_->foldMemoryOperand(MI, FoldOps, Slot) - : tii_->foldMemoryOperand(MI, FoldOps, DefMI); + MachineInstr *fmi = isSS ? tii_->foldMemoryOperand(*mf_, MI, FoldOps, Slot) + : tii_->foldMemoryOperand(*mf_, MI, FoldOps, DefMI); if (fmi) { + // Remember this instruction uses the spill slot. + if (isSS) vrm.addSpillSlotUse(Slot, fmi); + // Attempt to fold the memory reference into the instruction. If // we can do this, we don't need to insert spill code. if (lv_) lv_->instructionChanged(MI, fmi); else - LiveVariables::transferKillDeadInfo(MI, fmi, mri_); + fmi->copyKillDeadInfo(MI, tri_); MachineBasicBlock &MBB = *MI->getParent(); - if (isSS && !mf_->getFrameInfo()->isFixedObjectIndex(Slot)) + if (isSS && !mf_->getFrameInfo()->isImmutableObjectIndex(Slot)) vrm.virtFolded(Reg, MI, fmi, (VirtRegMap::ModRef)MRInfo); vrm.transferSpillPts(MI, fmi); vrm.transferRestorePts(MI, fmi); + vrm.transferEmergencySpills(MI, fmi); mi2iMap_.erase(MI); i2miMap_[InstrIdx /InstrSlots::NUM] = fmi; mi2iMap_[fmi] = InstrIdx; @@ -735,15 +903,18 @@ bool LiveIntervals::tryFoldMemoryOperand(MachineInstr* &MI, /// canFoldMemoryOperand - Returns true if the specified load / store /// folding is possible. bool LiveIntervals::canFoldMemoryOperand(MachineInstr *MI, - SmallVector &Ops) const { + SmallVector &Ops, + bool ReMat) const { + // Filter the list of operand indexes that are to be folded. Abort if + // any operand will prevent folding. + unsigned MRInfo = 0; SmallVector FoldOps; - for (unsigned i = 0, e = Ops.size(); i != e; ++i) { - unsigned OpIdx = Ops[i]; - // FIXME: fold subreg use. - if (MI->getOperand(OpIdx).getSubReg()) - return false; - FoldOps.push_back(OpIdx); - } + if (FilterFoldedOps(MI, Ops, MRInfo, FoldOps)) + return false; + + // It's only legal to remat for a use, not a def. + if (ReMat && (MRInfo & VirtRegMap::isMod)) + return false; return tii_->canFoldMemoryOperand(MI, FoldOps); } @@ -765,21 +936,47 @@ bool LiveIntervals::intervalIsInOneMBB(const LiveInterval &li) const { return true; } +/// rewriteImplicitOps - Rewrite implicit use operands of MI (i.e. uses of +/// interval on to-be re-materialized operands of MI) with new register. +void LiveIntervals::rewriteImplicitOps(const LiveInterval &li, + MachineInstr *MI, unsigned NewVReg, + VirtRegMap &vrm) { + // There is an implicit use. That means one of the other operand is + // being remat'ed and the remat'ed instruction has li.reg as an + // use operand. Make sure we rewrite that as well. + for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { + MachineOperand &MO = MI->getOperand(i); + if (!MO.isRegister()) + continue; + unsigned Reg = MO.getReg(); + if (Reg == 0 || TargetRegisterInfo::isPhysicalRegister(Reg)) + continue; + if (!vrm.isReMaterialized(Reg)) + continue; + MachineInstr *ReMatMI = vrm.getReMaterializedMI(Reg); + MachineOperand *UseMO = ReMatMI->findRegisterUseOperand(li.reg); + if (UseMO) + UseMO->setReg(NewVReg); + } +} + /// rewriteInstructionForSpills, rewriteInstructionsForSpills - Helper functions /// for addIntervalsForSpills to rewrite uses / defs for the given live range. bool LiveIntervals:: -rewriteInstructionForSpills(const LiveInterval &li, bool TrySplit, - unsigned id, unsigned index, unsigned end, MachineInstr *MI, +rewriteInstructionForSpills(const LiveInterval &li, const VNInfo *VNI, + bool TrySplit, unsigned index, unsigned end, MachineInstr *MI, MachineInstr *ReMatOrigDefMI, MachineInstr *ReMatDefMI, unsigned Slot, int LdSlot, bool isLoad, bool isLoadSS, bool DefIsReMat, bool CanDelete, - VirtRegMap &vrm, MachineRegisterInfo &RegInfo, + VirtRegMap &vrm, const TargetRegisterClass* rc, SmallVector &ReMatIds, - unsigned &NewVReg, bool &HasDef, bool &HasUse, const MachineLoopInfo *loopInfo, + unsigned &NewVReg, unsigned ImpUse, bool &HasDef, bool &HasUse, std::map &MBBVRegsMap, - std::vector &NewLIs) { + std::vector &NewLIs, float &SSWeight) { + MachineBasicBlock *MBB = MI->getParent(); + unsigned loopDepth = loopInfo->getLoopDepth(MBB); bool CanFold = false; RestartInstruction: for (unsigned i = 0; i != MI->getNumOperands(); ++i) { @@ -788,7 +985,7 @@ rewriteInstructionForSpills(const LiveInterval &li, bool TrySplit, continue; unsigned Reg = mop.getReg(); unsigned RegI = Reg; - if (Reg == 0 || MRegisterInfo::isPhysicalRegister(Reg)) + if (Reg == 0 || TargetRegisterInfo::isPhysicalRegister(Reg)) continue; if (Reg != li.reg) continue; @@ -839,7 +1036,7 @@ rewriteInstructionForSpills(const LiveInterval &li, bool TrySplit, if (!MOj.isRegister()) continue; unsigned RegJ = MOj.getReg(); - if (RegJ == 0 || MRegisterInfo::isPhysicalRegister(RegJ)) + if (RegJ == 0 || TargetRegisterInfo::isPhysicalRegister(RegJ)) continue; if (RegJ == RegI) { Ops.push_back(j); @@ -848,7 +1045,14 @@ rewriteInstructionForSpills(const LiveInterval &li, bool TrySplit, } } - 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) { @@ -859,35 +1063,45 @@ rewriteInstructionForSpills(const LiveInterval &li, bool TrySplit, HasUse = false; HasDef = false; CanFold = false; + if (isRemoved(MI)) { + SSWeight -= Weight; + break; + } goto RestartInstruction; } } else { - CanFold = canFoldMemoryOperand(MI, Ops); + // 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; if (NewVReg == 0) { - NewVReg = RegInfo.createVirtualRegister(rc); + NewVReg = mri_->createVirtualRegister(rc); vrm.grow(); CreatedNewVReg = true; } mop.setReg(NewVReg); + if (mop.isImplicit()) + rewriteImplicitOps(li, MI, NewVReg, vrm); // Reuse NewVReg for other reads. - for (unsigned j = 0, e = Ops.size(); j != e; ++j) - MI->getOperand(Ops[j]).setReg(NewVReg); + for (unsigned j = 0, e = Ops.size(); j != e; ++j) { + MachineOperand &mopj = MI->getOperand(Ops[j]); + mopj.setReg(NewVReg); + if (mopj.isImplicit()) + rewriteImplicitOps(li, MI, NewVReg, vrm); + } if (CreatedNewVReg) { if (DefIsReMat) { vrm.setVirtIsReMaterialized(NewVReg, ReMatDefMI/*, CanDelete*/); - if (ReMatIds[id] == VirtRegMap::MAX_STACK_SLOT) { + if (ReMatIds[VNI->id] == VirtRegMap::MAX_STACK_SLOT) { // Each valnum may have its own remat id. - ReMatIds[id] = vrm.assignVirtReMatId(NewVReg); + ReMatIds[VNI->id] = vrm.assignVirtReMatId(NewVReg); } else { - vrm.assignVirtReMatId(NewVReg, ReMatIds[id]); + vrm.assignVirtReMatId(NewVReg, ReMatIds[VNI->id]); } if (!CanDelete || (HasUse && HasDef)) { // If this is a two-addr instruction then its use operands are @@ -906,6 +1120,11 @@ rewriteInstructionForSpills(const LiveInterval &li, bool TrySplit, vrm.assignVirt2StackSlot(NewVReg, Slot); } + // Re-matting an instruction with virtual register use. Add the + // register as an implicit use on the use MI. + if (DefIsReMat && ImpUse) + MI->addOperand(MachineOperand::CreateReg(ImpUse, false, true)); + // create a new register interval for this spill / remat. LiveInterval &nI = getOrCreateInterval(NewVReg); if (CreatedNewVReg) { @@ -938,7 +1157,7 @@ rewriteInstructionForSpills(const LiveInterval &li, bool TrySplit, } DOUT << "\t\t\t\tAdded new interval: "; - nI.print(DOUT, mri_); + nI.print(DOUT, tri_); DOUT << '\n'; } return CanFold; @@ -955,15 +1174,23 @@ bool LiveIntervals::anyKillInMBBAfterIdx(const LiveInterval &li, 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; +/// RewriteInfo - Keep track of machine instrs that will be rewritten +/// during spilling. +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; } - return VNI; + }; } void LiveIntervals:: @@ -972,7 +1199,7 @@ rewriteInstructionsForSpills(const LiveInterval &li, bool TrySplit, MachineInstr *ReMatOrigDefMI, MachineInstr *ReMatDefMI, unsigned Slot, int LdSlot, bool isLoad, bool isLoadSS, bool DefIsReMat, bool CanDelete, - VirtRegMap &vrm, MachineRegisterInfo &RegInfo, + VirtRegMap &vrm, const TargetRegisterClass* rc, SmallVector &ReMatIds, const MachineLoopInfo *loopInfo, @@ -981,23 +1208,62 @@ rewriteInstructionsForSpills(const LiveInterval &li, bool TrySplit, BitVector &RestoreMBBs, std::map > &RestoreIdxes, std::map &MBBVRegsMap, - std::vector &NewLIs) { + std::vector &NewLIs, float &SSWeight) { bool AllCanFold = true; unsigned NewVReg = 0; - unsigned index = getBaseIndex(I->start); + unsigned start = getBaseIndex(I->start); unsigned end = getBaseIndex(I->end-1) + InstrSlots::NUM; - for (; index != end; index += InstrSlots::NUM) { - // skip deleted instructions - while (index != end && !getInstructionFromIndex(index)) - index += InstrSlots::NUM; - if (index == end) break; - MachineInstr *MI = getInstructionFromIndex(index); + // First collect all the def / use in this live range that will be rewritten. + // Make sure they are sorted according to instruction index. + std::vector RewriteMIs; + for (MachineRegisterInfo::reg_iterator ri = mri_->reg_begin(li.reg), + re = mri_->reg_end(); ri != re; ) { + MachineInstr *MI = &*ri; + MachineOperand &O = ri.getOperand(); + ++ri; + assert(!O.isImplicit() && "Spilling register that's used as implicit use?"); + unsigned index = getInstructionIndex(MI); + if (index < start || index >= end) + continue; + RewriteMIs.push_back(RewriteInfo(index, MI, O.isUse(), O.isDef())); + } + std::sort(RewriteMIs.begin(), RewriteMIs.end(), RewriteInfoCompare()); + + unsigned ImpUse = DefIsReMat ? getReMatImplicitUse(li, ReMatDefMI) : 0; + // Now rewrite the defs and uses. + for (unsigned i = 0, e = RewriteMIs.size(); i != e; ) { + RewriteInfo &rwi = RewriteMIs[i]; + ++i; + unsigned index = rwi.Index; + bool MIHasUse = rwi.HasUse; + bool MIHasDef = rwi.HasDef; + MachineInstr *MI = rwi.MI; + // If MI def and/or use the same register multiple times, then there + // are multiple entries. + unsigned NumUses = MIHasUse; + while (i != e && RewriteMIs[i].MI == MI) { + assert(RewriteMIs[i].Index == index); + bool isUse = RewriteMIs[i].HasUse; + if (isUse) ++NumUses; + MIHasUse |= isUse; + MIHasDef |= RewriteMIs[i].HasDef; + ++i; + } MachineBasicBlock *MBB = MI->getParent(); + + if (ImpUse && MI != ReMatDefMI) { + // Re-matting an instruction with virtual register use. Update the + // register interval's spill weight to HUGE_VALF to prevent it from + // being spilled. + LiveInterval &ImpLi = getInterval(ImpUse); + ImpLi.weight = HUGE_VALF; + } + + unsigned MBBId = MBB->getNumber(); unsigned ThisVReg = 0; if (TrySplit) { - std::map::const_iterator NVI = - MBBVRegsMap.find(MBB->getNumber()); + std::map::const_iterator NVI = MBBVRegsMap.find(MBBId); if (NVI != MBBVRegsMap.end()) { ThisVReg = NVI->second; // One common case: @@ -1008,18 +1274,6 @@ rewriteInstructionsForSpills(const LiveInterval &li, bool TrySplit, // = use // It's better to start a new interval to avoid artifically // extend the new interval. - // FIXME: Too slow? Can we fix it after rewriteInstructionsForSpills? - bool MIHasUse = false; - bool MIHasDef = false; - for (unsigned i = 0; i != MI->getNumOperands(); ++i) { - MachineOperand& mop = MI->getOperand(i); - if (!mop.isRegister() || mop.getReg() != li.reg) - continue; - if (mop.isUse()) - MIHasUse = true; - else - MIHasDef = true; - } if (MIHasDef && !MIHasUse) { MBBVRegsMap.erase(MBB->getNumber()); ThisVReg = 0; @@ -1041,11 +1295,11 @@ rewriteInstructionsForSpills(const LiveInterval &li, bool TrySplit, bool HasDef = false; bool HasUse = false; - bool CanFold = rewriteInstructionForSpills(li, TrySplit, I->valno->id, - index, end, MI, ReMatOrigDefMI, ReMatDefMI, - Slot, LdSlot, isLoad, isLoadSS, DefIsReMat, - CanDelete, vrm, RegInfo, rc, ReMatIds, NewVReg, - HasDef, HasUse, loopInfo, MBBVRegsMap, NewLIs); + 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, SSWeight); if (!HasDef && !HasUse) continue; @@ -1060,7 +1314,6 @@ rewriteInstructionsForSpills(const LiveInterval &li, bool TrySplit, } // Keep track of the last def and first use in each MBB. - unsigned MBBId = MBB->getNumber(); if (HasDef) { if (MI != ReMatOrigDefMI || !CanDelete) { bool HasKill = false; @@ -1068,7 +1321,7 @@ rewriteInstructionsForSpills(const LiveInterval &li, bool TrySplit, 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)); } @@ -1168,10 +1421,45 @@ void LiveIntervals::eraseRestoreInfo(int Id, int index, unsigned vr, Restores[i].index = -1; } +/// handleSpilledImpDefs - Remove IMPLICIT_DEF instructions which are being +/// spilled and create empty intervals for their uses. +void +LiveIntervals::handleSpilledImpDefs(const LiveInterval &li, VirtRegMap &vrm, + const TargetRegisterClass* rc, + std::vector &NewLIs) { + for (MachineRegisterInfo::reg_iterator ri = mri_->reg_begin(li.reg), + re = mri_->reg_end(); ri != re; ) { + MachineOperand &O = ri.getOperand(); + MachineInstr *MI = &*ri; + ++ri; + if (O.isDef()) { + assert(MI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF && + "Register def was not rewritten?"); + RemoveMachineInstrFromMaps(MI); + vrm.RemoveMachineInstrFromMaps(MI); + MI->eraseFromParent(); + } else { + // This must be an use of an implicit_def so it's not part of the live + // interval. Create a new empty live interval for it. + // FIXME: Can we simply erase some of the instructions? e.g. Stores? + unsigned NewVReg = mri_->createVirtualRegister(rc); + vrm.grow(); + vrm.setIsImplicitlyDefined(NewVReg); + NewLIs.push_back(&getOrCreateInterval(NewVReg)); + for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { + MachineOperand &MO = MI->getOperand(i); + if (MO.isReg() && MO.getReg() == li.reg) + MO.setReg(NewVReg); + } + } + } +} + std::vector 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(); @@ -1180,9 +1468,12 @@ addIntervalsForSpills(const LiveInterval &li, "attempt to spill already spilled interval!"); DOUT << "\t\t\t\tadding intervals for spills for interval: "; - li.print(DOUT, mri_); + 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 > SpillIdxes; @@ -1190,8 +1481,7 @@ addIntervalsForSpills(const LiveInterval &li, std::map > RestoreIdxes; std::map MBBVRegsMap; std::vector NewLIs; - MachineRegisterInfo &RegInfo = mf_->getRegInfo(); - const TargetRegisterClass* rc = RegInfo.getRegClass(li.reg); + const TargetRegisterClass* rc = mri_->getRegClass(li.reg); unsigned NumValNums = li.getNumValNums(); SmallVector ReMatDefs; @@ -1236,18 +1526,21 @@ addIntervalsForSpills(const LiveInterval &li, // Note ReMatOrigDefMI has already been deleted. rewriteInstructionsForSpills(li, false, I, NULL, ReMatDefMI, Slot, LdSlot, isLoad, isLoadSS, DefIsReMat, - false, vrm, RegInfo, rc, ReMatIds, loopInfo, + 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, RegInfo, rc, ReMatIds, loopInfo, + 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; } @@ -1310,20 +1603,24 @@ addIntervalsForSpills(const LiveInterval &li, (DefIsReMat && ReMatDefMI->getDesc().isSimpleLoad()); rewriteInstructionsForSpills(li, TrySplit, I, ReMatOrigDefMI, ReMatDefMI, Slot, LdSlot, isLoad, isLoadSS, DefIsReMat, - CanDelete, vrm, RegInfo, rc, ReMatIds, loopInfo, + CanDelete, vrm, rc, ReMatIds, loopInfo, SpillMBBs, SpillIdxes, RestoreMBBs, RestoreIdxes, - MBBVRegsMap, NewLIs); + MBBVRegsMap, NewLIs, SSWeight); } // Insert spills / restores if we are splitting. - if (!TrySplit) + if (!TrySplit) { + handleSpilledImpDefs(li, vrm, rc, NewLIs); return NewLIs; + } SmallPtrSet AddedKill; SmallVector Ops; if (NeedStackSlot) { int Id = SpillMBBs.find_first(); while (Id != -1) { + MachineBasicBlock *MBB = mf_->getBlockNumbered(Id); + unsigned loopDepth = loopInfo->getLoopDepth(MBB); std::vector &spills = SpillIdxes[Id]; for (unsigned i = 0, e = spills.size(); i != e; ++i) { int index = spills[i].index; @@ -1370,14 +1667,20 @@ addIntervalsForSpills(const LiveInterval &li, } } - // Else tell the spiller to issue a spill. + // Otherwise tell the spiller to issue a spill. 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); } @@ -1385,6 +1688,9 @@ addIntervalsForSpills(const LiveInterval &li, int Id = RestoreMBBs.find_first(); while (Id != -1) { + MachineBasicBlock *MBB = mf_->getBlockNumbered(Id); + unsigned loopDepth = loopInfo->getLoopDepth(MBB); + std::vector &restores = RestoreIdxes[Id]; for (unsigned i = 0, e = restores.size(); i != e; ++i) { int index = restores[i].index; @@ -1392,6 +1698,7 @@ addIntervalsForSpills(const LiveInterval &li, continue; unsigned VReg = restores[i].vreg; LiveInterval &nI = getOrCreateInterval(VReg); + bool isReMat = vrm.isReMaterialized(VReg); MachineInstr *MI = getInstructionFromIndex(index); bool CanFold = false; Ops.clear(); @@ -1415,7 +1722,7 @@ addIntervalsForSpills(const LiveInterval &li, // 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); @@ -1425,6 +1732,16 @@ addIntervalsForSpills(const LiveInterval &li, if (isLoadSS || ReMatDefMI->getDesc().isSimpleLoad()) Folded = tryFoldMemoryOperand(MI, vrm, ReMatDefMI, index, Ops, isLoadSS, LdSlot, VReg); + unsigned ImpUse = getReMatImplicitUse(li, ReMatDefMI); + if (ImpUse) { + // Re-matting an instruction with virtual register use. Add the + // register as an implicit use on the use MI and update the register + // interval's spill weight to HUGE_VALF to prevent it from being + // spilled. + LiveInterval &ImpLi = getInterval(ImpUse); + ImpLi.weight = HUGE_VALF; + MI->addOperand(MachineOperand::CreateReg(ImpUse, false, true)); + } } } // If folding is not possible / failed, then tell the spiller to issue a @@ -1433,6 +1750,10 @@ addIntervalsForSpills(const LiveInterval &li, 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); } @@ -1448,10 +1769,10 @@ addIntervalsForSpills(const LiveInterval &li, LiveRange *LR = &LI->ranges[LI->ranges.size()-1]; unsigned LastUseIdx = getBaseIndex(LR->end); MachineInstr *LastUse = getInstructionFromIndex(LastUseIdx); - int UseIdx = LastUse->findRegisterUseOperandIdx(LI->reg); + int UseIdx = LastUse->findRegisterUseOperandIdx(LI->reg, false); assert(UseIdx != -1); - if (LastUse->getDesc().getOperandConstraint(UseIdx, TOI::TIED_TO) == - -1) { + if (LastUse->getOperand(UseIdx).isImplicit() || + LastUse->getDesc().getOperandConstraint(UseIdx,TOI::TIED_TO) == -1){ LastUse->getOperand(UseIdx).setIsKill(); vrm.addKillPoint(LI->reg, LastUseIdx); } @@ -1460,5 +1781,99 @@ addIntervalsForSpills(const LiveInterval &li, } } + handleSpilledImpDefs(li, vrm, rc, RetNewLIs); return RetNewLIs; } + +/// hasAllocatableSuperReg - Return true if the specified physical register has +/// any super register that's allocatable. +bool LiveIntervals::hasAllocatableSuperReg(unsigned Reg) const { + for (const unsigned* AS = tri_->getSuperRegisters(Reg); *AS; ++AS) + if (allocatableRegs_[*AS] && hasInterval(*AS)) + return true; + return false; +} + +/// getRepresentativeReg - Find the largest super register of the specified +/// physical register. +unsigned LiveIntervals::getRepresentativeReg(unsigned Reg) const { + // Find the largest super-register that is allocatable. + unsigned BestReg = Reg; + for (const unsigned* AS = tri_->getSuperRegisters(Reg); *AS; ++AS) { + unsigned SuperReg = *AS; + if (!hasAllocatableSuperReg(SuperReg) && hasInterval(SuperReg)) { + BestReg = SuperReg; + break; + } + } + return BestReg; +} + +/// getNumConflictsWithPhysReg - Return the number of uses and defs of the +/// specified interval that conflicts with the specified physical register. +unsigned LiveIntervals::getNumConflictsWithPhysReg(const LiveInterval &li, + unsigned PhysReg) const { + unsigned NumConflicts = 0; + const LiveInterval &pli = getInterval(getRepresentativeReg(PhysReg)); + for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(li.reg), + E = mri_->reg_end(); I != E; ++I) { + MachineOperand &O = I.getOperand(); + MachineInstr *MI = O.getParent(); + unsigned Index = getInstructionIndex(MI); + if (pli.liveAt(Index)) + ++NumConflicts; + } + return NumConflicts; +} + +/// spillPhysRegAroundRegDefsUses - Spill the specified physical register +/// around all defs and uses of the specified interval. +void LiveIntervals::spillPhysRegAroundRegDefsUses(const LiveInterval &li, + unsigned PhysReg, VirtRegMap &vrm) { + unsigned SpillReg = getRepresentativeReg(PhysReg); + + for (const unsigned *AS = tri_->getAliasSet(PhysReg); *AS; ++AS) + // If there are registers which alias PhysReg, but which are not a + // sub-register of the chosen representative super register. Assert + // since we can't handle it yet. + assert(*AS == SpillReg || !allocatableRegs_[*AS] || + tri_->isSuperRegister(*AS, SpillReg)); + + LiveInterval &pli = getInterval(SpillReg); + SmallPtrSet SeenMIs; + for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(li.reg), + E = mri_->reg_end(); I != E; ++I) { + MachineOperand &O = I.getOperand(); + MachineInstr *MI = O.getParent(); + if (SeenMIs.count(MI)) + continue; + SeenMIs.insert(MI); + unsigned Index = getInstructionIndex(MI); + if (pli.liveAt(Index)) { + vrm.addEmergencySpill(SpillReg, MI); + pli.removeRange(getLoadIndex(Index), getStoreIndex(Index)+1); + for (const unsigned* AS = tri_->getSubRegisters(SpillReg); *AS; ++AS) { + if (!hasInterval(*AS)) + continue; + LiveInterval &spli = getInterval(*AS); + if (spli.liveAt(Index)) + spli.removeRange(getLoadIndex(Index), getStoreIndex(Index)+1); + } + } + } +} + +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; +}