X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;ds=sidebyside;f=lib%2FCodeGen%2FMachineBasicBlock.cpp;h=98359b198545cd5ab71aff46e62f9cf6c5c3b93e;hb=4ceab42509518746afef0370e7aba230736a80f5;hp=0464dca086bfd2dde6d1985ef3d25df05f9de0bc;hpb=b720be6a50f4e1b3280d2b029ee38dda14577525;p=oota-llvm.git diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp index 0464dca086b..98359b19854 100644 --- a/lib/CodeGen/MachineBasicBlock.cpp +++ b/lib/CodeGen/MachineBasicBlock.cpp @@ -12,46 +12,53 @@ //===----------------------------------------------------------------------===// #include "llvm/CodeGen/MachineBasicBlock.h" -#include "llvm/BasicBlock.h" +#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/CodeGen/LiveIntervalAnalysis.h" #include "llvm/CodeGen/LiveVariables.h" #include "llvm/CodeGen/MachineDominators.h" #include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineInstrBuilder.h" #include "llvm/CodeGen/MachineLoopInfo.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/CodeGen/SlotIndexes.h" +#include "llvm/IR/BasicBlock.h" +#include "llvm/IR/DataLayout.h" #include "llvm/MC/MCAsmInfo.h" #include "llvm/MC/MCContext.h" -#include "llvm/Target/TargetRegisterInfo.h" -#include "llvm/Target/TargetData.h" -#include "llvm/Target/TargetInstrInfo.h" -#include "llvm/Target/TargetMachine.h" -#include "llvm/Assembly/Writer.h" -#include "llvm/ADT/SmallString.h" -#include "llvm/ADT/SmallPtrSet.h" #include "llvm/Support/Debug.h" -#include "llvm/Support/LeakDetector.h" #include "llvm/Support/raw_ostream.h" +#include "llvm/Target/TargetInstrInfo.h" +#include "llvm/Target/TargetMachine.h" +#include "llvm/Target/TargetRegisterInfo.h" +#include "llvm/Target/TargetSubtargetInfo.h" #include using namespace llvm; +#define DEBUG_TYPE "codegen" + MachineBasicBlock::MachineBasicBlock(MachineFunction &mf, const BasicBlock *bb) : BB(bb), Number(-1), xParent(&mf), Alignment(0), IsLandingPad(false), - AddressTaken(false) { + AddressTaken(false), CachedMCSymbol(nullptr) { Insts.Parent = this; } MachineBasicBlock::~MachineBasicBlock() { - LeakDetector::removeGarbageObject(this); } /// getSymbol - Return the MCSymbol for this basic block. /// MCSymbol *MachineBasicBlock::getSymbol() const { - const MachineFunction *MF = getParent(); - MCContext &Ctx = MF->getContext(); - const char *Prefix = Ctx.getAsmInfo().getPrivateGlobalPrefix(); - return Ctx.GetOrCreateSymbol(Twine(Prefix) + "BB" + - Twine(MF->getFunctionNumber()) + "_" + - Twine(getNumber())); + if (!CachedMCSymbol) { + const MachineFunction *MF = getParent(); + MCContext &Ctx = MF->getContext(); + const char *Prefix = Ctx.getAsmInfo()->getPrivateLabelPrefix(); + CachedMCSymbol = Ctx.GetOrCreateSymbol(Twine(Prefix) + "BB" + + Twine(MF->getFunctionNumber()) + + "_" + Twine(getNumber())); + } + + return CachedMCSymbol; } @@ -76,14 +83,11 @@ 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); } @@ -91,30 +95,26 @@ void ilist_traits::removeNodeFromList(MachineBasicBlock *N) { /// 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() == 0 && "machine instruction already in a basic block"); + assert(!N->getParent() && "machine instruction already in a basic block"); N->setParent(Parent); // Add the instruction's register operands to their corresponding // 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. void ilist_traits::removeNodeFromList(MachineInstr *N) { - assert(N->getParent() != 0 && "machine instruction not in a basic block"); + assert(N->getParent() && "machine instruction not in a basic block"); // Remove from the use/def lists. if (MachineFunction *MF = N->getParent()->getParent()) N->RemoveRegOperandsFromUseLists(MF->getRegInfo()); - N->setParent(0); - - LeakDetector::addGarbageObject(N); + N->setParent(nullptr); } /// transferNodesFromList (MI) - When moving a range of instructions from one @@ -145,18 +145,19 @@ MachineBasicBlock::iterator MachineBasicBlock::getFirstNonPHI() { instr_iterator I = instr_begin(), E = instr_end(); while (I != E && I->isPHI()) ++I; - assert(!I->isInsideBundle() && "First non-phi MI cannot be inside a bundle!"); + assert((I == E || !I->isInsideBundle()) && + "First non-phi MI cannot be inside a bundle!"); return I; } MachineBasicBlock::iterator MachineBasicBlock::SkipPHIsAndLabels(MachineBasicBlock::iterator I) { iterator E = end(); - while (I != E && (I->isPHI() || I->isLabel() || I->isDebugValue())) + while (I != E && (I->isPHI() || I->isPosition() || I->isDebugValue())) ++I; // FIXME: This needs to change if we wish to bundle labels / dbg_values // inside the bundle. - assert(!I->isInsideBundle() && + assert((I == E || !I->isInsideBundle()) && "First non-phi / non-label instruction is inside a bundle!"); return I; } @@ -221,11 +222,11 @@ MachineBasicBlock::getLastNonDebugInstr() const { const MachineBasicBlock *MachineBasicBlock::getLandingPadSuccessor() const { // A block with a landing pad successor only has one other successor. if (succ_size() > 2) - return 0; + return nullptr; for (const_succ_iterator I = succ_begin(), E = succ_end(); I != E; ++I) if ((*I)->isLandingPad()) return *I; - return 0; + return nullptr; } #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) @@ -269,7 +270,7 @@ void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) const { const char *Comma = ""; if (const BasicBlock *LBB = getBasicBlock()) { OS << Comma << "derived from LLVM BB "; - WriteAsOperand(OS, LBB, /*PrintType=*/false); + LBB->printAsOperand(OS, /*PrintType=*/false); Comma = ", "; } if (isLandingPad()) { OS << Comma << "EH LANDING PAD"; Comma = ", "; } @@ -280,7 +281,7 @@ 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:"; @@ -306,7 +307,7 @@ void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) const { OS << '\t'; if (I->isInsideBundle()) OS << " * "; - I->print(OS, &getParent()->getTarget()); + I->print(OS); } // Print the successors of this block according to the CFG. @@ -322,6 +323,10 @@ void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) 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); @@ -334,6 +339,38 @@ bool MachineBasicBlock::isLiveIn(unsigned Reg) const { return I != livein_end(); } +unsigned +MachineBasicBlock::addLiveIn(unsigned PhysReg, const TargetRegisterClass *RC) { + assert(getParent() && "MBB must be inserted in function"); + assert(TargetRegisterInfo::isPhysicalRegister(PhysReg) && "Expected physreg"); + assert(RC && "Register class is required"); + assert((isLandingPad() || this == &getParent()->front()) && + "Only the entry block and landing pads can have physreg live ins"); + + bool LiveIn = isLiveIn(PhysReg); + iterator I = SkipPHIsAndLabels(begin()), E = end(); + MachineRegisterInfo &MRI = getParent()->getRegInfo(); + const TargetInstrInfo &TII = *getParent()->getSubtarget().getInstrInfo(); + + // Look for an existing copy. + if (LiveIn) + for (;I != E && I->isCopy(); ++I) + if (I->getOperand(1).getReg() == PhysReg) { + unsigned VirtReg = I->getOperand(0).getReg(); + if (!MRI.constrainRegClass(VirtReg, RC)) + llvm_unreachable("Incompatible live-in register class."); + return VirtReg; + } + + // No luck, create a virtual register. + unsigned VirtReg = MRI.createVirtualRegister(RC); + BuildMI(*this, I, DebugLoc(), TII.get(TargetOpcode::COPY), VirtReg) + .addReg(PhysReg, RegState::Kill); + if (!LiveIn) + addLiveIn(PhysReg); + return VirtReg; +} + void MachineBasicBlock::moveBefore(MachineBasicBlock *NewAfter) { getParent()->splice(NewAfter, this); } @@ -344,11 +381,11 @@ 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; - MachineBasicBlock *TBB = 0, *FBB = 0; + MachineBasicBlock *TBB = nullptr, *FBB = nullptr; SmallVector Cond; DebugLoc dl; // FIXME: this is nowhere bool B = TII->AnalyzeBranch(*this, TBB, FBB, Cond); @@ -379,7 +416,7 @@ void MachineBasicBlock::updateTerminator() { // Finally update the unconditional successor to be reached via a branch // if it would not be reached by fallthrough. if (!isLayoutSuccessor(TBB)) - TII->InsertBranch(*this, TBB, 0, Cond, dl); + TII->InsertBranch(*this, TBB, nullptr, Cond, dl); } } else { if (FBB) { @@ -390,16 +427,16 @@ void MachineBasicBlock::updateTerminator() { if (TII->ReverseBranchCondition(Cond)) return; TII->RemoveBranch(*this); - TII->InsertBranch(*this, FBB, 0, Cond, dl); + TII->InsertBranch(*this, FBB, nullptr, Cond, dl); } else if (isLayoutSuccessor(FBB)) { TII->RemoveBranch(*this); - TII->InsertBranch(*this, TBB, 0, Cond, dl); + TII->InsertBranch(*this, TBB, nullptr, Cond, dl); } } else { // Walk through the successors and find the successor which is not // a landing pad and is not the conditional branch destination (in TBB) // as the fallthrough successor. - MachineBasicBlock *FallthroughBB = 0; + MachineBasicBlock *FallthroughBB = nullptr; for (succ_iterator SI = succ_begin(), SE = succ_end(); SI != SE; ++SI) { if ((*SI)->isLandingPad() || *SI == TBB) continue; @@ -417,7 +454,7 @@ void MachineBasicBlock::updateTerminator() { // Finally update the unconditional successor to be reached via a branch // if it would not be reached by fallthrough. if (!isLayoutSuccessor(TBB)) - TII->InsertBranch(*this, TBB, 0, Cond, dl); + TII->InsertBranch(*this, TBB, nullptr, Cond, dl); return; } @@ -426,11 +463,11 @@ void MachineBasicBlock::updateTerminator() { if (TII->ReverseBranchCondition(Cond)) { // We can't reverse the condition, add an unconditional branch. Cond.clear(); - TII->InsertBranch(*this, FallthroughBB, 0, Cond, dl); + TII->InsertBranch(*this, FallthroughBB, nullptr, Cond, dl); return; } TII->RemoveBranch(*this); - TII->InsertBranch(*this, FallthroughBB, 0, Cond, dl); + TII->InsertBranch(*this, FallthroughBB, nullptr, Cond, dl); } else if (!isLayoutSuccessor(FallthroughBB)) { TII->RemoveBranch(*this); TII->InsertBranch(*this, TBB, FallthroughBB, Cond, dl); @@ -582,7 +619,7 @@ bool MachineBasicBlock::isSuccessor(const MachineBasicBlock *MBB) const { bool MachineBasicBlock::isLayoutSuccessor(const MachineBasicBlock *MBB) const { MachineFunction::const_iterator I(this); - return llvm::next(I) == MachineFunction::const_iterator(MBB); + return std::next(I) == MachineFunction::const_iterator(MBB); } bool MachineBasicBlock::canFallThrough() { @@ -597,9 +634,9 @@ bool MachineBasicBlock::canFallThrough() { return false; // Analyze the branches, if any, at the end of the block. - MachineBasicBlock *TBB = 0, *FBB = 0; + 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 @@ -610,7 +647,7 @@ bool MachineBasicBlock::canFallThrough() { } // If there is no branch, control always falls through. - if (TBB == 0) return true; + if (!TBB) return true; // If there is some explicit branch to the fallthrough block, it can obviously // reach, even though the branch should get folded to fall through implicitly. @@ -624,7 +661,7 @@ bool MachineBasicBlock::canFallThrough() { // Otherwise, if it is conditional and has no explicit false block, it falls // through. - return FBB == 0; + return FBB == nullptr; } MachineBasicBlock * @@ -632,18 +669,23 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { // Splitting the critical edge to a landing pad block is non-trivial. Don't do // it in this generic function. if (Succ->isLandingPad()) - return NULL; + return nullptr; MachineFunction *MF = getParent(); DebugLoc dl; // FIXME: this is nowhere + // Performance might be harmed on HW that implements branching using exec mask + // where both sides of the branches are always executed. + if (MF->getTarget().requiresStructuredCFG()) + return nullptr; + // 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(); - MachineBasicBlock *TBB = 0, *FBB = 0; + const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo(); + MachineBasicBlock *TBB = nullptr, *FBB = nullptr; SmallVector Cond; if (TII->AnalyzeBranch(*this, TBB, FBB, Cond)) - return NULL; + return nullptr; // Avoid bugpoint weirdness: A block may end with a conditional branch but // jumps to the same MBB is either case. We have duplicate CFG edges in that @@ -652,16 +694,23 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { if (TBB && TBB == FBB) { DEBUG(dbgs() << "Won't split critical edge after degenerate BB#" << getNumber() << '\n'); - return NULL; + return nullptr; } MachineBasicBlock *NMBB = MF->CreateMachineBasicBlock(); - MF->insert(llvm::next(MachineFunction::iterator(this)), NMBB); + MF->insert(std::next(MachineFunction::iterator(this)), NMBB); DEBUG(dbgs() << "Splitting critical edge:" " BB#" << getNumber() << " -- BB#" << NMBB->getNumber() << " -- BB#" << Succ->getNumber() << '\n'); + LiveIntervals *LIS = P->getAnalysisIfAvailable(); + SlotIndexes *Indexes = P->getAnalysisIfAvailable(); + if (LIS) + LIS->insertMBBInMaps(NMBB); + else if (Indexes) + Indexes->insertMBBInMaps(NMBB); + // On some targets like Mips, branches may kill virtual registers. Make sure // that LiveVariables is properly updated after updateTerminator replaces the // terminators. @@ -688,14 +737,68 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { } } + SmallVector UsedRegs; + if (LIS) { + for (instr_iterator I = getFirstInstrTerminator(), E = instr_end(); + I != E; ++I) { + MachineInstr *MI = I; + + for (MachineInstr::mop_iterator OI = MI->operands_begin(), + OE = MI->operands_end(); OI != OE; ++OI) { + if (!OI->isReg() || OI->getReg() == 0) + continue; + + unsigned Reg = OI->getReg(); + if (std::find(UsedRegs.begin(), UsedRegs.end(), Reg) == UsedRegs.end()) + UsedRegs.push_back(Reg); + } + } + } + ReplaceUsesOfBlockWith(Succ, NMBB); + + // If updateTerminator() removes instructions, we need to remove them from + // SlotIndexes. + SmallVector Terminators; + if (Indexes) { + for (instr_iterator I = getFirstInstrTerminator(), E = instr_end(); + I != E; ++I) + Terminators.push_back(I); + } + updateTerminator(); + if (Indexes) { + SmallVector NewTerminators; + for (instr_iterator I = getFirstInstrTerminator(), E = instr_end(); + I != E; ++I) + NewTerminators.push_back(I); + + for (SmallVectorImpl::iterator I = Terminators.begin(), + E = Terminators.end(); I != E; ++I) { + if (std::find(NewTerminators.begin(), NewTerminators.end(), *I) == + NewTerminators.end()) + Indexes->removeMachineInstrFromMaps(*I); + } + } + // Insert unconditional "jump Succ" instruction in NMBB if necessary. NMBB->addSuccessor(Succ); if (!NMBB->isLayoutSuccessor(Succ)) { Cond.clear(); - MF->getTarget().getInstrInfo()->InsertBranch(*NMBB, Succ, NULL, Cond, dl); + MF->getSubtarget().getInstrInfo()->InsertBranch(*NMBB, Succ, nullptr, Cond, + dl); + + if (Indexes) { + for (instr_iterator I = NMBB->instr_begin(), E = NMBB->instr_end(); + I != E; ++I) { + // Some instructions may have been moved to NMBB by updateTerminator(), + // so we first remove any instruction that already has an index. + if (Indexes->hasIndex(I)) + Indexes->removeMachineInstrFromMaps(I); + Indexes->insertMachineInstrInMaps(I); + } + } } // Fix PHI nodes in Succ so they refer to NMBB instead of this @@ -712,7 +815,7 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { NMBB->addLiveIn(*I); // 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()) { @@ -730,33 +833,71 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { LV->addNewBlock(NMBB, this, Succ); } - 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; + 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. + + bool isLastMBB = + std::next(MachineFunction::iterator(NMBB)) == getParent()->end(); + + SlotIndex StartIndex = Indexes->getMBBEndIdx(this); + SlotIndex PrevIndex = StartIndex.getPrevSlot(); + SlotIndex EndIndex = Indexes->getMBBEndIdx(NMBB); + + // Find the registers used from NMBB in PHIs in Succ. + SmallSet PHISrcRegs; + for (MachineBasicBlock::instr_iterator + I = Succ->instr_begin(), E = Succ->instr_end(); + I != E && I->isPHI(); ++I) { + for (unsigned ni = 1, ne = I->getNumOperands(); ni != ne; ni += 2) { + if (I->getOperand(ni+1).getMBB() == NMBB) { + MachineOperand &MO = I->getOperand(ni); + unsigned Reg = MO.getReg(); + PHISrcRegs.insert(Reg); + if (MO.isUndef()) + continue; + + LiveInterval &LI = LIS->getInterval(Reg); + VNInfo *VNI = LI.getVNInfoAt(PrevIndex); + assert(VNI && "PHI sources should be live out of their predecessors."); + LI.addSegment(LiveInterval::Segment(StartIndex, EndIndex, VNI)); + } } } - // We know "this" dominates the newly created basic block. - MachineDomTreeNode *NewDTNode = MDT->addNewBlock(NMBB, this); + MachineRegisterInfo *MRI = &getParent()->getRegInfo(); + for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) { + unsigned Reg = TargetRegisterInfo::index2VirtReg(i); + if (PHISrcRegs.count(Reg) || !LIS->hasInterval(Reg)) + continue; + + LiveInterval &LI = LIS->getInterval(Reg); + if (!LI.liveAt(PrevIndex)) + continue; + + bool isLiveOut = LI.liveAt(LIS->getMBBStartIdx(Succ)); + if (isLiveOut && isLastMBB) { + VNInfo *VNI = LI.getVNInfoAt(PrevIndex); + assert(VNI && "LiveInterval should have VNInfo where it is live."); + LI.addSegment(LiveInterval::Segment(StartIndex, EndIndex, VNI)); + } else if (!isLiveOut && !isLastMBB) { + LI.removeSegment(StartIndex, EndIndex); + } + } - // 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); + // Update all intervals for registers whose uses may have been modified by + // updateTerminator(). + LIS->repairIntervalsInRange(this, getFirstTerminator(), end(), UsedRegs); } + if (MachineDominatorTree *MDT = + P->getAnalysisIfAvailable()) + MDT->recordSplitCriticalEdge(this, Succ, NMBB); + if (MachineLoopInfo *MLI = P->getAnalysisIfAvailable()) if (MachineLoop *TIL = MLI->getLoopFor(this)) { // If one or the other blocks were not in a loop, the new block is not @@ -787,40 +928,42 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { return NMBB; } -MachineBasicBlock::iterator -MachineBasicBlock::erase(MachineBasicBlock::iterator I) { - if (I->isBundle()) { - MachineBasicBlock::iterator E = llvm::next(I); - return Insts.erase(I.getInstrIterator(), E.getInstrIterator()); - } - - return Insts.erase(I.getInstrIterator()); +/// Prepare MI to be removed from its bundle. This fixes bundle flags on MI's +/// neighboring instructions so the bundle won't be broken by removing MI. +static void unbundleSingleMI(MachineInstr *MI) { + // Removing the first instruction in a bundle. + if (MI->isBundledWithSucc() && !MI->isBundledWithPred()) + MI->unbundleFromSucc(); + // Removing the last instruction in a bundle. + if (MI->isBundledWithPred() && !MI->isBundledWithSucc()) + MI->unbundleFromPred(); + // If MI is not bundled, or if it is internal to a bundle, the neighbor flags + // are already fine. } -MachineInstr *MachineBasicBlock::remove(MachineInstr *I) { - if (I->isBundle()) { - instr_iterator MII = llvm::next(I); - iterator E = end(); - while (MII != E && MII->isInsideBundle()) { - MachineInstr *MI = &*MII++; - Insts.remove(MI); - } - } +MachineBasicBlock::instr_iterator +MachineBasicBlock::erase(MachineBasicBlock::instr_iterator I) { + unbundleSingleMI(I); + return Insts.erase(I); +} - return Insts.remove(I); +MachineInstr *MachineBasicBlock::remove_instr(MachineInstr *MI) { + unbundleSingleMI(MI); + MI->clearFlag(MachineInstr::BundledPred); + MI->clearFlag(MachineInstr::BundledSucc); + return Insts.remove(MI); } -void MachineBasicBlock::splice(MachineBasicBlock::iterator where, - MachineBasicBlock *Other, - MachineBasicBlock::iterator From) { - if (From->isBundle()) { - MachineBasicBlock::iterator To = llvm::next(From); - Insts.splice(where.getInstrIterator(), Other->Insts, - From.getInstrIterator(), To.getInstrIterator()); - return; +MachineBasicBlock::instr_iterator +MachineBasicBlock::insert(instr_iterator I, MachineInstr *MI) { + assert(!MI->isBundledWithPred() && !MI->isBundledWithSucc() && + "Cannot insert instruction with bundle flags"); + // Set the bundle flags when inserting inside a bundle. + if (I != instr_end() && I->isBundledWithPred()) { + MI->setFlag(MachineInstr::BundledPred); + MI->setFlag(MachineInstr::BundledSucc); } - - Insts.splice(where.getInstrIterator(), Other->Insts, From.getInstrIterator()); + return Insts.insert(I, MI); } /// removeFromParent - This method unlinks 'this' from the containing function, @@ -891,13 +1034,13 @@ bool MachineBasicBlock::CorrectExtraCFGEdges(MachineBasicBlock *DestA, bool Changed = false; MachineFunction::iterator FallThru = - llvm::next(MachineFunction::iterator(this)); + std::next(MachineFunction::iterator(this)); - if (DestA == 0 && DestB == 0) { + if (!DestA && !DestB) { // Block falls through to successor. DestA = FallThru; DestB = FallThru; - } else if (DestA != 0 && DestB == 0) { + } else if (DestA && !DestB) { if (isCond) // Block ends in conditional jump that falls through to successor. DestB = FallThru; @@ -912,7 +1055,7 @@ 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); @@ -951,6 +1094,13 @@ uint32_t MachineBasicBlock::getSuccWeight(const_succ_iterator Succ) const { return *getWeightIterator(Succ); } +/// Set successor weight of a given iterator. +void MachineBasicBlock::setSuccWeight(succ_iterator I, uint32_t weight) { + if (Weights.empty()) + return; + *getWeightIterator(I) = weight; +} + /// getWeightIterator - Return wight iterator corresonding to the I successor /// iterator MachineBasicBlock::weight_iterator MachineBasicBlock:: @@ -971,8 +1121,79 @@ getWeightIterator(MachineBasicBlock::const_succ_iterator I) const { return Weights.begin() + index; } -void llvm::WriteAsOperand(raw_ostream &OS, const MachineBasicBlock *MBB, - bool t) { - OS << "BB#" << MBB->getNumber(); -} +/// Return whether (physical) register "Reg" has been ined and not ed +/// as of just before "MI". +/// +/// Search is localised to a neighborhood of +/// Neighborhood instructions before (searching for defs or kills) and N +/// instructions after (searching just for defs) MI. +MachineBasicBlock::LivenessQueryResult +MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI, + unsigned Reg, MachineInstr *MI, + unsigned Neighborhood) { + unsigned N = Neighborhood; + MachineBasicBlock *MBB = MI->getParent(); + + // Start by searching backwards from MI, looking for kills, reads or defs. + + MachineBasicBlock::iterator I(MI); + // If this is the first insn in the block, don't search backwards. + if (I != MBB->begin()) { + do { + --I; + + MachineOperandIteratorBase::PhysRegInfo Analysis = + MIOperands(I).analyzePhysReg(Reg, TRI); + + if (Analysis.Defines) + // Outputs happen after inputs so they take precedence if both are + // present. + return Analysis.DefinesDead ? LQR_Dead : LQR_Live; + + if (Analysis.Kills || Analysis.Clobbers) + // Register killed, so isn't live. + return LQR_Dead; + + else if (Analysis.ReadsOverlap) + // Defined or read without a previous kill - live. + return Analysis.Reads ? LQR_Live : LQR_OverlappingLive; + + } while (I != MBB->begin() && --N > 0); + } + // Did we get to the start of the block? + if (I == MBB->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)) + return (*RAI == Reg) ? LQR_Live : LQR_OverlappingLive; + } + + return LQR_Dead; + } + + N = Neighborhood; + + // Try searching forwards from MI, looking for reads or defs. + I = MachineBasicBlock::iterator(MI); + // 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) { + MachineOperandIteratorBase::PhysRegInfo Analysis = + MIOperands(I).analyzePhysReg(Reg, TRI); + + if (Analysis.ReadsOverlap) + // Used, therefore must have been live. + return (Analysis.Reads) ? + LQR_Live : LQR_OverlappingLive; + + else if (Analysis.Clobbers || Analysis.Defines) + // Defined (but not read) therefore cannot have been live. + return LQR_Dead; + } + } + + // At this point we have no idea of the liveness of the register. + return LQR_Unknown; +}