X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=lib%2FCodeGen%2FMachineBasicBlock.cpp;h=c30b95a6b2d6af3dc7a0b71277bc0c06c13d8e66;hp=08fef5ffaf44ea9e9dd6ade8b611fea7803f5b01;hb=fbf4c2b2e1b9e9d78bab2a199ab5082205aed9ae;hpb=d0fb0f421fbc052ca13eed8b39bc8a0d3f9de0c1 diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp index 08fef5ffaf4..c30b95a6b2d 100644 --- a/lib/CodeGen/MachineBasicBlock.cpp +++ b/lib/CodeGen/MachineBasicBlock.cpp @@ -24,7 +24,7 @@ #include "llvm/CodeGen/SlotIndexes.h" #include "llvm/IR/BasicBlock.h" #include "llvm/IR/DataLayout.h" -#include "llvm/IR/LeakDetector.h" +#include "llvm/IR/ModuleSlotTracker.h" #include "llvm/MC/MCAsmInfo.h" #include "llvm/MC/MCContext.h" #include "llvm/Support/Debug.h" @@ -32,6 +32,7 @@ #include "llvm/Target/TargetInstrInfo.h" #include "llvm/Target/TargetMachine.h" #include "llvm/Target/TargetRegisterInfo.h" +#include "llvm/Target/TargetSubtargetInfo.h" #include using namespace llvm; @@ -44,18 +45,15 @@ MachineBasicBlock::MachineBasicBlock(MachineFunction &mf, const BasicBlock *bb) } MachineBasicBlock::~MachineBasicBlock() { - LeakDetector::removeGarbageObject(this); } -/// getSymbol - Return the MCSymbol for this basic block. -/// +/// Return the MCSymbol for this basic block. MCSymbol *MachineBasicBlock::getSymbol() const { if (!CachedMCSymbol) { const MachineFunction *MF = getParent(); MCContext &Ctx = MF->getContext(); - const TargetMachine &TM = MF->getTarget(); - const char *Prefix = TM.getDataLayout()->getPrivateGlobalPrefix(); - CachedMCSymbol = Ctx.GetOrCreateSymbol(Twine(Prefix) + "BB" + + const char *Prefix = Ctx.getAsmInfo()->getPrivateLabelPrefix(); + CachedMCSymbol = Ctx.getOrCreateSymbol(Twine(Prefix) + "BB" + Twine(MF->getFunctionNumber()) + "_" + Twine(getNumber())); } @@ -69,9 +67,9 @@ raw_ostream &llvm::operator<<(raw_ostream &OS, const MachineBasicBlock &MBB) { return OS; } -/// addNodeToList (MBB) - When an MBB is added to an MF, we need to update the -/// parent pointer of the MBB, the MBB numbering, and any instructions in the -/// MBB to be on the right operand list for registers. +/// When an MBB is added to an MF, we need to update the parent pointer of the +/// MBB, the MBB numbering, and any instructions in the MBB to be on the right +/// operand list for registers. /// /// MBBs start out as #-1. When a MBB is added to a MachineFunction, it /// gets the next available unique MBB number. If it is removed from a @@ -85,20 +83,15 @@ void ilist_traits::addNodeToList(MachineBasicBlock *N) { for (MachineBasicBlock::instr_iterator I = N->instr_begin(), E = N->instr_end(); I != E; ++I) I->AddRegOperandsToUseLists(RegInfo); - - LeakDetector::removeGarbageObject(N); } void ilist_traits::removeNodeFromList(MachineBasicBlock *N) { N->getParent()->removeFromMBBNumbering(N->Number); N->Number = -1; - LeakDetector::addGarbageObject(N); } - -/// addNodeToList (MI) - When we add an instruction to a basic block -/// list, we update its parent pointer and add its operands from reg use/def -/// lists if appropriate. +/// When we add an instruction to a basic block list, we update its parent +/// pointer and add its operands from reg use/def lists if appropriate. void ilist_traits::addNodeToList(MachineInstr *N) { assert(!N->getParent() && "machine instruction already in a basic block"); N->setParent(Parent); @@ -107,13 +100,10 @@ void ilist_traits::addNodeToList(MachineInstr *N) { // use/def lists. MachineFunction *MF = Parent->getParent(); N->AddRegOperandsToUseLists(MF->getRegInfo()); - - LeakDetector::removeGarbageObject(N); } -/// removeNodeFromList (MI) - When we remove an instruction from a basic block -/// list, we update its parent pointer and remove its operands from reg use/def -/// lists if appropriate. +/// When we remove an instruction from a basic block list, we update its parent +/// pointer and remove its operands from reg use/def lists if appropriate. void ilist_traits::removeNodeFromList(MachineInstr *N) { assert(N->getParent() && "machine instruction not in a basic block"); @@ -122,13 +112,10 @@ void ilist_traits::removeNodeFromList(MachineInstr *N) { N->RemoveRegOperandsFromUseLists(MF->getRegInfo()); N->setParent(nullptr); - - LeakDetector::addGarbageObject(N); } -/// transferNodesFromList (MI) - When moving a range of instructions from one -/// MBB list to another, we need to update the parent pointers and the use/def -/// lists. +/// When moving a range of instructions from one MBB list to another, we need to +/// update the parent pointers and the use/def lists. void ilist_traits:: transferNodesFromList(ilist_traits &fromList, ilist_iterator first, @@ -180,9 +167,8 @@ MachineBasicBlock::iterator MachineBasicBlock::getFirstTerminator() { return I; } -MachineBasicBlock::const_iterator -MachineBasicBlock::getFirstTerminator() const { - const_iterator B = begin(), E = end(), I = E; +MachineBasicBlock::instr_iterator MachineBasicBlock::getFirstInstrTerminator() { + instr_iterator B = instr_begin(), E = instr_end(), I = E; while (I != B && ((--I)->isTerminator() || I->isDebugValue())) ; /*noop */ while (I != E && !I->isTerminator()) @@ -190,11 +176,10 @@ MachineBasicBlock::getFirstTerminator() const { return I; } -MachineBasicBlock::instr_iterator MachineBasicBlock::getFirstInstrTerminator() { - instr_iterator B = instr_begin(), E = instr_end(), I = E; - while (I != B && ((--I)->isTerminator() || I->isDebugValue())) - ; /*noop */ - while (I != E && !I->isTerminator()) +MachineBasicBlock::iterator MachineBasicBlock::getFirstNonDebugInstr() { + // Skip over begin-of-block dbg_value instructions. + iterator I = begin(), E = end(); + while (I != E && I->isDebugValue()) ++I; return I; } @@ -213,21 +198,6 @@ MachineBasicBlock::iterator MachineBasicBlock::getLastNonDebugInstr() { return end(); } -MachineBasicBlock::const_iterator -MachineBasicBlock::getLastNonDebugInstr() const { - // Skip over end-of-block dbg_value instructions. - const_instr_iterator B = instr_begin(), I = instr_end(); - while (I != B) { - --I; - // Return instruction that starts a bundle. - if (I->isDebugValue() || I->isInsideBundle()) - continue; - return I; - } - // The block is all debug values. - return end(); -} - const MachineBasicBlock *MachineBasicBlock::getLandingPadSuccessor() const { // A block with a landing pad successor only has one other successor. if (succ_size() > 2) @@ -259,7 +229,7 @@ std::string MachineBasicBlock::getFullName() const { if (getBasicBlock()) Name += getBasicBlock()->getName(); else - Name += (Twine("BB") + Twine(getNumber())).str(); + Name += ("BB" + Twine(getNumber())).str(); return Name; } @@ -270,6 +240,20 @@ void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) const { << " is null\n"; return; } + const Function *F = MF->getFunction(); + const Module *M = F ? F->getParent() : nullptr; + ModuleSlotTracker MST(M); + print(OS, MST, Indexes); +} + +void MachineBasicBlock::print(raw_ostream &OS, ModuleSlotTracker &MST, + SlotIndexes *Indexes) const { + const MachineFunction *MF = getParent(); + if (!MF) { + OS << "Can't print out MachineBasicBlock because parent MachineFunction" + << " is null\n"; + return; + } if (Indexes) OS << Indexes->getMBBStartIdx(this) << '\t'; @@ -279,7 +263,7 @@ void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) const { const char *Comma = ""; if (const BasicBlock *LBB = getBasicBlock()) { OS << Comma << "derived from LLVM BB "; - LBB->printAsOperand(OS, /*PrintType=*/false); + LBB->printAsOperand(OS, /*PrintType=*/false, MST); Comma = ", "; } if (isLandingPad()) { OS << Comma << "EH LANDING PAD"; Comma = ", "; } @@ -290,12 +274,13 @@ void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) const { OS << '\n'; - const TargetRegisterInfo *TRI = MF->getTarget().getRegisterInfo(); + const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo(); if (!livein_empty()) { if (Indexes) OS << '\t'; OS << " Live Ins:"; - for (livein_iterator I = livein_begin(),E = livein_end(); I != E; ++I) - OS << ' ' << PrintReg(*I, TRI); + for (unsigned LI : make_range(livein_begin(), livein_end())) { + OS << ' ' << PrintReg(LI, TRI); + } OS << '\n'; } // Print the preds of this block according to the CFG. @@ -316,7 +301,7 @@ void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) const { OS << '\t'; if (I->isInsideBundle()) OS << " * "; - I->print(OS, &getParent()->getTarget()); + I->print(OS, MST); } // Print the successors of this block according to the CFG. @@ -332,24 +317,24 @@ void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) const { } } -void MachineBasicBlock::printAsOperand(raw_ostream &OS, bool /*PrintType*/) const { +void MachineBasicBlock::printAsOperand(raw_ostream &OS, + bool /*PrintType*/) const { OS << "BB#" << getNumber(); } -void MachineBasicBlock::removeLiveIn(unsigned Reg) { - std::vector::iterator I = - std::find(LiveIns.begin(), LiveIns.end(), Reg); +void MachineBasicBlock::removeLiveIn(MCPhysReg Reg) { + LiveInVector::iterator I = std::find(LiveIns.begin(), LiveIns.end(), Reg); if (I != LiveIns.end()) LiveIns.erase(I); } -bool MachineBasicBlock::isLiveIn(unsigned Reg) const { +bool MachineBasicBlock::isLiveIn(MCPhysReg Reg) const { livein_iterator I = std::find(livein_begin(), livein_end(), Reg); return I != livein_end(); } unsigned -MachineBasicBlock::addLiveIn(unsigned PhysReg, const TargetRegisterClass *RC) { +MachineBasicBlock::addLiveIn(MCPhysReg PhysReg, const TargetRegisterClass *RC) { assert(getParent() && "MBB must be inserted in function"); assert(TargetRegisterInfo::isPhysicalRegister(PhysReg) && "Expected physreg"); assert(RC && "Register class is required"); @@ -359,7 +344,7 @@ MachineBasicBlock::addLiveIn(unsigned PhysReg, const TargetRegisterClass *RC) { bool LiveIn = isLiveIn(PhysReg); iterator I = SkipPHIsAndLabels(begin()), E = end(); MachineRegisterInfo &MRI = getParent()->getRegInfo(); - const TargetInstrInfo &TII = *getParent()->getTarget().getInstrInfo(); + const TargetInstrInfo &TII = *getParent()->getSubtarget().getInstrInfo(); // Look for an existing copy. if (LiveIn) @@ -390,7 +375,7 @@ void MachineBasicBlock::moveAfter(MachineBasicBlock *NewBefore) { } void MachineBasicBlock::updateTerminator() { - const TargetInstrInfo *TII = getParent()->getTarget().getInstrInfo(); + const TargetInstrInfo *TII = getParent()->getSubtarget().getInstrInfo(); // A block with no successors has no concerns with fall-through edges. if (this->succ_empty()) return; @@ -456,8 +441,8 @@ void MachineBasicBlock::updateTerminator() { // We fallthrough to the same basic block as the conditional jump // targets. Remove the conditional jump, leaving unconditional // fallthrough. - // FIXME: This does not seem like a reasonable pattern to support, but it - // has been seen in the wild coming out of degenerate ARM test cases. + // FIXME: This does not seem like a reasonable pattern to support, but + // it has been seen in the wild coming out of degenerate ARM test cases. TII->RemoveBranch(*this); // Finally update the unconditional successor to be reached via a branch @@ -495,9 +480,9 @@ void MachineBasicBlock::addSuccessor(MachineBasicBlock *succ, uint32_t weight) { if (weight != 0 || !Weights.empty()) Weights.push_back(weight); - Successors.push_back(succ); - succ->addPredecessor(this); - } + Successors.push_back(succ); + succ->addPredecessor(this); +} void MachineBasicBlock::removeSuccessor(MachineBasicBlock *succ) { succ->removePredecessor(this); @@ -645,7 +630,7 @@ bool MachineBasicBlock::canFallThrough() { // Analyze the branches, if any, at the end of the block. MachineBasicBlock *TBB = nullptr, *FBB = nullptr; SmallVector Cond; - const TargetInstrInfo *TII = getParent()->getTarget().getInstrInfo(); + const TargetInstrInfo *TII = getParent()->getSubtarget().getInstrInfo(); if (TII->AnalyzeBranch(*this, TBB, FBB, Cond)) { // If we couldn't analyze the branch, examine the last instruction. // If the block doesn't end in a known control barrier, assume fallthrough @@ -690,7 +675,7 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { // We may need to update this's terminator, but we can't do that if // AnalyzeBranch fails. If this uses a jump table, we won't touch it. - const TargetInstrInfo *TII = MF->getTarget().getInstrInfo(); + const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo(); MachineBasicBlock *TBB = nullptr, *FBB = nullptr; SmallVector Cond; if (TII->AnalyzeBranch(*this, TBB, FBB, Cond)) @@ -795,7 +780,8 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { NMBB->addSuccessor(Succ); if (!NMBB->isLayoutSuccessor(Succ)) { Cond.clear(); - MF->getTarget().getInstrInfo()->InsertBranch(*NMBB, Succ, nullptr, Cond, dl); + MF->getSubtarget().getInstrInfo()->InsertBranch(*NMBB, Succ, nullptr, Cond, + dl); if (Indexes) { for (instr_iterator I = NMBB->instr_begin(), E = NMBB->instr_end(); @@ -818,12 +804,11 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { i->getOperand(ni+1).setMBB(NMBB); // Inherit live-ins from the successor - for (MachineBasicBlock::livein_iterator I = Succ->livein_begin(), - E = Succ->livein_end(); I != E; ++I) - NMBB->addLiveIn(*I); + for (unsigned LI : Succ->liveins()) + NMBB->addLiveIn(LI); // Update LiveVariables. - const TargetRegisterInfo *TRI = MF->getTarget().getRegisterInfo(); + const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo(); if (LV) { // Restore kills of virtual registers that were killed by the terminators. while (!KilledRegs.empty()) { @@ -844,10 +829,10 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { if (LIS) { // After splitting the edge and updating SlotIndexes, live intervals may be // in one of two situations, depending on whether this block was the last in - // the function. If the original block was the last in the function, all live - // intervals will end prior to the beginning of the new split block. If the - // original block was not at the end of the function, all live intervals will - // extend to the end of the new split block. + // the function. If the original block was the last in the function, all + // live intervals will end prior to the beginning of the new split block. If + // the original block was not at the end of the function, all live intervals + // will extend to the end of the new split block. bool isLastMBB = std::next(MachineFunction::iterator(NMBB)) == getParent()->end(); @@ -871,7 +856,8 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { LiveInterval &LI = LIS->getInterval(Reg); VNInfo *VNI = LI.getVNInfoAt(PrevIndex); - assert(VNI && "PHI sources should be live out of their predecessors."); + assert(VNI && + "PHI sources should be live out of their predecessors."); LI.addSegment(LiveInterval::Segment(StartIndex, EndIndex, VNI)); } } @@ -903,31 +889,8 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { } if (MachineDominatorTree *MDT = - P->getAnalysisIfAvailable()) { - // Update dominator information. - MachineDomTreeNode *SucccDTNode = MDT->getNode(Succ); - - bool IsNewIDom = true; - for (const_pred_iterator PI = Succ->pred_begin(), E = Succ->pred_end(); - PI != E; ++PI) { - MachineBasicBlock *PredBB = *PI; - if (PredBB == NMBB) - continue; - if (!MDT->dominates(SucccDTNode, MDT->getNode(PredBB))) { - IsNewIDom = false; - break; - } - } - - // We know "this" dominates the newly created basic block. - MachineDomTreeNode *NewDTNode = MDT->addNewBlock(NMBB, this); - - // If all the other predecessors of "Succ" are dominated by "Succ" itself - // then the new block is the new immediate dominator of "Succ". Otherwise, - // the new block doesn't dominate anything. - if (IsNewIDom) - MDT->changeImmediateDominator(SucccDTNode, NewDTNode); - } + P->getAnalysisIfAvailable()) + MDT->recordSplitCriticalEdge(this, Succ, NMBB); if (MachineLoopInfo *MLI = P->getAnalysisIfAvailable()) if (MachineLoop *TIL = MLI->getLoopFor(this)) { @@ -997,25 +960,22 @@ MachineBasicBlock::insert(instr_iterator I, MachineInstr *MI) { return Insts.insert(I, MI); } -/// removeFromParent - This method unlinks 'this' from the containing function, -/// and returns it, but does not delete it. +/// This method unlinks 'this' from the containing function, and returns it, but +/// does not delete it. MachineBasicBlock *MachineBasicBlock::removeFromParent() { assert(getParent() && "Not embedded in a function!"); getParent()->remove(this); return this; } - -/// eraseFromParent - This method unlinks 'this' from the containing function, -/// and deletes it. +/// This method unlinks 'this' from the containing function, and deletes it. void MachineBasicBlock::eraseFromParent() { assert(getParent() && "Not embedded in a function!"); getParent()->erase(this); } - -/// ReplaceUsesOfBlockWith - Given a machine basic block that branched to -/// 'Old', change the code and CFG so that it branches to 'New' instead. +/// Given a machine basic block that branched to 'Old', change the code and CFG +/// so that it branches to 'New' instead. void MachineBasicBlock::ReplaceUsesOfBlockWith(MachineBasicBlock *Old, MachineBasicBlock *New) { assert(Old != New && "Cannot replace self with self!"); @@ -1037,10 +997,9 @@ void MachineBasicBlock::ReplaceUsesOfBlockWith(MachineBasicBlock *Old, replaceSuccessor(Old, New); } -/// CorrectExtraCFGEdges - Various pieces of code can cause excess edges in the -/// CFG to be inserted. If we have proven that MBB can only branch to DestA and -/// DestB, remove any other MBB successors from the CFG. DestA and DestB can be -/// null. +/// Various pieces of code can cause excess edges in the CFG to be inserted. If +/// we have proven that MBB can only branch to DestA and DestB, remove any other +/// MBB successors from the CFG. DestA and DestB can be null. /// /// Besides DestA and DestB, retain other edges leading to LandingPads /// (currently there can be only one; we don't check or require that here). @@ -1086,7 +1045,7 @@ bool MachineBasicBlock::CorrectExtraCFGEdges(MachineBasicBlock *DestA, MachineBasicBlock::succ_iterator SI = succ_begin(); while (SI != succ_end()) { const MachineBasicBlock *MBB = *SI; - if (!SeenMBBs.insert(MBB) || + if (!SeenMBBs.insert(MBB).second || (MBB != DestA && MBB != DestB && !MBB->isLandingPad())) { // This is a superfluous edge, remove it. SI = removeSuccessor(SI); @@ -1099,8 +1058,8 @@ bool MachineBasicBlock::CorrectExtraCFGEdges(MachineBasicBlock *DestA, return Changed; } -/// findDebugLoc - find the next valid DebugLoc starting at MBBI, skipping -/// any DBG_VALUE instructions. Return UnknownLoc if there is none. +/// Find the next valid DebugLoc starting at MBBI, skipping any DBG_VALUE +/// instructions. Return UnknownLoc if there is none. DebugLoc MachineBasicBlock::findDebugLoc(instr_iterator MBBI) { DebugLoc DL; @@ -1116,8 +1075,7 @@ MachineBasicBlock::findDebugLoc(instr_iterator MBBI) { return DL; } -/// getSuccWeight - Return weight of the edge from this block to MBB. -/// +/// Return weight of the edge from this block to MBB. uint32_t MachineBasicBlock::getSuccWeight(const_succ_iterator Succ) const { if (Weights.empty()) return 0; @@ -1132,8 +1090,7 @@ void MachineBasicBlock::setSuccWeight(succ_iterator I, uint32_t weight) { *getWeightIterator(I) = weight; } -/// getWeightIterator - Return wight iterator corresonding to the I successor -/// iterator +/// Return wight iterator corresonding to the I successor iterator. MachineBasicBlock::weight_iterator MachineBasicBlock:: getWeightIterator(MachineBasicBlock::succ_iterator I) { assert(Weights.size() == Successors.size() && "Async weight list!"); @@ -1142,8 +1099,7 @@ getWeightIterator(MachineBasicBlock::succ_iterator I) { return Weights.begin() + index; } -/// getWeightIterator - Return wight iterator corresonding to the I successor -/// iterator +/// Return wight iterator corresonding to the I successor iterator. MachineBasicBlock::const_weight_iterator MachineBasicBlock:: getWeightIterator(MachineBasicBlock::const_succ_iterator I) const { assert(Weights.size() == Successors.size() && "Async weight list!"); @@ -1160,21 +1116,19 @@ getWeightIterator(MachineBasicBlock::const_succ_iterator I) const { /// instructions after (searching just for defs) MI. MachineBasicBlock::LivenessQueryResult MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI, - unsigned Reg, MachineInstr *MI, - unsigned Neighborhood) { + unsigned Reg, const_iterator Before, + unsigned Neighborhood) const { unsigned N = Neighborhood; - MachineBasicBlock *MBB = MI->getParent(); - - // Start by searching backwards from MI, looking for kills, reads or defs. - MachineBasicBlock::iterator I(MI); + // Start by searching backwards from Before, looking for kills, reads or defs. + const_iterator I(Before); // If this is the first insn in the block, don't search backwards. - if (I != MBB->begin()) { + if (I != begin()) { do { --I; MachineOperandIteratorBase::PhysRegInfo Analysis = - MIOperands(I).analyzePhysReg(Reg, TRI); + ConstMIOperands(I).analyzePhysReg(Reg, TRI); if (Analysis.Defines) // Outputs happen after inputs so they take precedence if both are @@ -1189,15 +1143,15 @@ MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI, // Defined or read without a previous kill - live. return Analysis.Reads ? LQR_Live : LQR_OverlappingLive; - } while (I != MBB->begin() && --N > 0); + } while (I != begin() && --N > 0); } // Did we get to the start of the block? - if (I == MBB->begin()) { + if (I == begin()) { // If so, the register's state is definitely defined by the live-in state. for (MCRegAliasIterator RAI(Reg, TRI, /*IncludeSelf=*/true); RAI.isValid(); ++RAI) { - if (MBB->isLiveIn(*RAI)) + if (isLiveIn(*RAI)) return (*RAI == Reg) ? LQR_Live : LQR_OverlappingLive; } @@ -1206,13 +1160,13 @@ MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI, N = Neighborhood; - // Try searching forwards from MI, looking for reads or defs. - I = MachineBasicBlock::iterator(MI); + // Try searching forwards from Before, looking for reads or defs. + I = const_iterator(Before); // If this is the last insn in the block, don't search forwards. - if (I != MBB->end()) { - for (++I; I != MBB->end() && N > 0; ++I, --N) { + if (I != end()) { + for (++I; I != end() && N > 0; ++I, --N) { MachineOperandIteratorBase::PhysRegInfo Analysis = - MIOperands(I).analyzePhysReg(Reg, TRI); + ConstMIOperands(I).analyzePhysReg(Reg, TRI); if (Analysis.ReadsOverlap) // Used, therefore must have been live.