X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FMachineBasicBlock.cpp;h=3d36dc18e38b1eb22218970fe0c0e291205c1408;hb=5be77762a3aa434ee877b0a03b98b5c3a7571918;hp=4dc8173bd760365c718ecd0a8d84460f56b8a41d;hpb=5a96b3dad2f634c9081c8b2b6c2575441dc5a2bd;p=oota-llvm.git diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp index 4dc8173bd76..3d36dc18e38 100644 --- a/lib/CodeGen/MachineBasicBlock.cpp +++ b/lib/CodeGen/MachineBasicBlock.cpp @@ -12,30 +12,33 @@ //===----------------------------------------------------------------------===// #include "llvm/CodeGen/MachineBasicBlock.h" -#include "llvm/BasicBlock.h" +#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/Assembly/Writer.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 using namespace llvm; MachineBasicBlock::MachineBasicBlock(MachineFunction &mf, const BasicBlock *bb) : BB(bb), Number(-1), xParent(&mf), Alignment(0), IsLandingPad(false), - AddressTaken(false) { + AddressTaken(false), CachedMCSymbol(NULL) { Insts.Parent = this; } @@ -46,12 +49,16 @@ MachineBasicBlock::~MachineBasicBlock() { /// 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()->getPrivateGlobalPrefix(); + CachedMCSymbol = Ctx.GetOrCreateSymbol(Twine(Prefix) + "BB" + + Twine(MF->getFunctionNumber()) + + "_" + Twine(getNumber())); + } + + return CachedMCSymbol; } @@ -73,8 +80,8 @@ void ilist_traits::addNodeToList(MachineBasicBlock *N) { // Make sure the instructions have their operands in the reginfo lists. MachineRegisterInfo &RegInfo = MF.getRegInfo(); - for (MachineBasicBlock::insn_iterator I = N->insn_begin(), E = N->insn_end(); - I != E; ++I) + for (MachineBasicBlock::instr_iterator + I = N->instr_begin(), E = N->instr_end(); I != E; ++I) I->AddRegOperandsToUseLists(RegInfo); LeakDetector::removeGarbageObject(N); @@ -109,7 +116,8 @@ void ilist_traits::removeNodeFromList(MachineInstr *N) { assert(N->getParent() != 0 && "machine instruction not in a basic block"); // Remove from the use/def lists. - N->RemoveRegOperandsFromUseLists(); + if (MachineFunction *MF = N->getParent()->getParent()) + N->RemoveRegOperandsFromUseLists(MF->getRegInfo()); N->setParent(0); @@ -141,55 +149,57 @@ void ilist_traits::deleteNode(MachineInstr* MI) { } MachineBasicBlock::iterator MachineBasicBlock::getFirstNonPHI() { - insn_iterator I = insn_begin(); - while (I != end() && I->isPHI()) + 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) { - while (I != end() && (I->isPHI() || I->isLabel() || I->isDebugValue())) + iterator E = end(); + while (I != E && (I->isPHI() || I->isLabel() || 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; } MachineBasicBlock::iterator MachineBasicBlock::getFirstTerminator() { - iterator I = end(); - while (I != begin() && ((--I)->isTerminator() || I->isDebugValue())) + iterator B = begin(), E = end(), I = E; + while (I != B && ((--I)->isTerminator() || I->isDebugValue())) ; /*noop */ - while (I != end() && !I->isTerminator()) + while (I != E && !I->isTerminator()) ++I; return I; } MachineBasicBlock::const_iterator MachineBasicBlock::getFirstTerminator() const { - const_iterator I = end(); - while (I != begin() && ((--I)->isTerminator() || I->isDebugValue())) + const_iterator B = begin(), E = end(), I = E; + while (I != B && ((--I)->isTerminator() || I->isDebugValue())) ; /*noop */ - while (I != end() && !I->isTerminator()) + while (I != E && !I->isTerminator()) ++I; return I; } -MachineBasicBlock::insn_iterator MachineBasicBlock::getFirstInsnTerminator() { - insn_iterator I = insn_end(); - while (I != insn_begin() && ((--I)->isTerminator() || I->isDebugValue())) +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 != insn_end() && !I->isTerminator()) + while (I != E && !I->isTerminator()) ++I; return I; } MachineBasicBlock::iterator MachineBasicBlock::getLastNonDebugInstr() { // Skip over end-of-block dbg_value instructions. - insn_iterator B = insn_begin(), I = insn_end(); + instr_iterator B = instr_begin(), I = instr_end(); while (I != B) { --I; // Return instruction that starts a bundle. @@ -204,7 +214,7 @@ MachineBasicBlock::iterator MachineBasicBlock::getLastNonDebugInstr() { MachineBasicBlock::const_iterator MachineBasicBlock::getLastNonDebugInstr() const { // Skip over end-of-block dbg_value instructions. - const_insn_iterator B = insn_begin(), I = insn_end(); + const_instr_iterator B = instr_begin(), I = instr_end(); while (I != B) { --I; // Return instruction that starts a bundle. @@ -226,9 +236,11 @@ const MachineBasicBlock *MachineBasicBlock::getLandingPadSuccessor() const { return 0; } +#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) void MachineBasicBlock::dump() const { print(dbgs()); } +#endif StringRef MachineBasicBlock::getName() const { if (const BasicBlock *LBB = getBasicBlock()) @@ -237,6 +249,18 @@ StringRef MachineBasicBlock::getName() const { return "(null)"; } +/// Return a hopefully unique identifier for this block. +std::string MachineBasicBlock::getFullName() const { + std::string Name; + if (getParent()) + Name = (getParent()->getName() + ":").str(); + if (getBasicBlock()) + Name += getBasicBlock()->getName(); + else + Name += (Twine("BB") + Twine(getNumber())).str(); + return Name; +} + void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) const { const MachineFunction *MF = getParent(); if (!MF) { @@ -258,11 +282,9 @@ void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) const { } if (isLandingPad()) { OS << Comma << "EH LANDING PAD"; Comma = ", "; } if (hasAddressTaken()) { OS << Comma << "ADDRESS TAKEN"; Comma = ", "; } - if (Alignment) { + if (Alignment) OS << Comma << "Align " << Alignment << " (" << (1u << Alignment) << " bytes)"; - Comma = ", "; - } OS << '\n'; @@ -283,13 +305,15 @@ void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) const { OS << '\n'; } - for (const_iterator I = begin(); I != end(); ++I) { + for (const_instr_iterator I = instr_begin(); I != instr_end(); ++I) { if (Indexes) { if (Indexes->hasIndex(I)) OS << Indexes->getInstructionIndex(I); OS << '\t'; } OS << '\t'; + if (I->isInsideBundle()) + OS << " * "; I->print(OS, &getParent()->getTarget()); } @@ -297,8 +321,11 @@ void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) const { if (!succ_empty()) { if (Indexes) OS << '\t'; OS << " Successors according to CFG:"; - for (const_succ_iterator SI = succ_begin(), E = succ_end(); SI != E; ++SI) + for (const_succ_iterator SI = succ_begin(), E = succ_end(); SI != E; ++SI) { OS << " BB#" << (*SI)->getNumber(); + if (!Weights.empty()) + OS << '(' << *getWeightIterator(SI) << ')'; + } OS << '\n'; } } @@ -306,8 +333,8 @@ void MachineBasicBlock::print(raw_ostream &OS, SlotIndexes *Indexes) const { void MachineBasicBlock::removeLiveIn(unsigned Reg) { std::vector::iterator I = std::find(LiveIns.begin(), LiveIns.end(), Reg); - assert(I != LiveIns.end() && "Not a live in!"); - LiveIns.erase(I); + if (I != LiveIns.end()) + LiveIns.erase(I); } bool MachineBasicBlock::isLiveIn(unsigned Reg) const { @@ -315,6 +342,38 @@ 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()->getTarget().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); } @@ -377,22 +436,44 @@ void MachineBasicBlock::updateTerminator() { TII->InsertBranch(*this, TBB, 0, 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; + for (succ_iterator SI = succ_begin(), SE = succ_end(); SI != SE; ++SI) { + if ((*SI)->isLandingPad() || *SI == TBB) + continue; + assert(!FallthroughBB && "Found more than one fallthrough successor."); + FallthroughBB = *SI; + } + if (!FallthroughBB && canFallThrough()) { + // 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. + TII->RemoveBranch(*this); + + // 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); + return; + } + // The block has a fallthrough conditional branch. - MachineBasicBlock *MBBA = *succ_begin(); - MachineBasicBlock *MBBB = *llvm::next(succ_begin()); - if (MBBA == TBB) std::swap(MBBB, MBBA); if (isLayoutSuccessor(TBB)) { if (TII->ReverseBranchCondition(Cond)) { // We can't reverse the condition, add an unconditional branch. Cond.clear(); - TII->InsertBranch(*this, MBBA, 0, Cond, dl); + TII->InsertBranch(*this, FallthroughBB, 0, Cond, dl); return; } TII->RemoveBranch(*this); - TII->InsertBranch(*this, MBBA, 0, Cond, dl); - } else if (!isLayoutSuccessor(MBBA)) { + TII->InsertBranch(*this, FallthroughBB, 0, Cond, dl); + } else if (!isLayoutSuccessor(FallthroughBB)) { TII->RemoveBranch(*this); - TII->InsertBranch(*this, TBB, MBBA, Cond, dl); + TII->InsertBranch(*this, TBB, FallthroughBB, Cond, dl); } } } @@ -442,18 +523,42 @@ MachineBasicBlock::removeSuccessor(succ_iterator I) { void MachineBasicBlock::replaceSuccessor(MachineBasicBlock *Old, MachineBasicBlock *New) { - uint32_t weight = 0; - succ_iterator SI = std::find(Successors.begin(), Successors.end(), Old); + if (Old == New) + return; - // If Weight list is empty it means we don't use it (disabled optimization). - if (!Weights.empty()) { - weight_iterator WI = getWeightIterator(SI); - weight = *WI; + succ_iterator E = succ_end(); + succ_iterator NewI = E; + succ_iterator OldI = E; + for (succ_iterator I = succ_begin(); I != E; ++I) { + if (*I == Old) { + OldI = I; + if (NewI != E) + break; + } + if (*I == New) { + NewI = I; + if (OldI != E) + break; + } } + assert(OldI != E && "Old is not a successor of this block"); + Old->removePredecessor(this); - // Update the successor information. - removeSuccessor(SI); - addSuccessor(New, weight); + // If New isn't already a successor, let it take Old's place. + if (NewI == E) { + New->addPredecessor(this); + *OldI = New; + return; + } + + // New is already a successor. + // Update its weight instead of adding a duplicate edge. + if (!Weights.empty()) { + weight_iterator OldWI = getWeightIterator(OldI); + *getWeightIterator(NewI) += *OldWI; + Weights.erase(OldWI); + } + Successors.erase(OldI); } void MachineBasicBlock::addPredecessor(MachineBasicBlock *pred) { @@ -472,14 +577,13 @@ void MachineBasicBlock::transferSuccessors(MachineBasicBlock *fromMBB) { while (!fromMBB->succ_empty()) { MachineBasicBlock *Succ = *fromMBB->succ_begin(); - uint32_t weight = 0; - + uint32_t Weight = 0; // If Weight list is empty it means we don't use it (disabled optimization). if (!fromMBB->Weights.empty()) - weight = *fromMBB->Weights.begin(); + Weight = *fromMBB->Weights.begin(); - addSuccessor(Succ, weight); + addSuccessor(Succ, Weight); fromMBB->removeSuccessor(Succ); } } @@ -491,12 +595,15 @@ MachineBasicBlock::transferSuccessorsAndUpdatePHIs(MachineBasicBlock *fromMBB) { while (!fromMBB->succ_empty()) { MachineBasicBlock *Succ = *fromMBB->succ_begin(); - addSuccessor(Succ); + uint32_t Weight = 0; + if (!fromMBB->Weights.empty()) + Weight = *fromMBB->Weights.begin(); + addSuccessor(Succ, Weight); fromMBB->removeSuccessor(Succ); // Fix up any PHI nodes in the successor. - for (MachineBasicBlock::insn_iterator MI = Succ->insn_begin(), - ME = Succ->insn_end(); MI != ME && MI->isPHI(); ++MI) + for (MachineBasicBlock::instr_iterator MI = Succ->instr_begin(), + ME = Succ->instr_end(); MI != ME && MI->isPHI(); ++MI) for (unsigned i = 2, e = MI->getNumOperands()+1; i != e; i += 2) { MachineOperand &MO = MI->getOperand(i); if (MO.getMBB() == fromMBB) @@ -505,9 +612,12 @@ MachineBasicBlock::transferSuccessorsAndUpdatePHIs(MachineBasicBlock *fromMBB) { } } +bool MachineBasicBlock::isPredecessor(const MachineBasicBlock *MBB) const { + return std::find(pred_begin(), pred_end(), MBB) != pred_end(); +} + bool MachineBasicBlock::isSuccessor(const MachineBasicBlock *MBB) const { - const_succ_iterator I = std::find(Successors.begin(), Successors.end(), MBB); - return I != Successors.end(); + return std::find(succ_begin(), succ_end(), MBB) != succ_end(); } bool MachineBasicBlock::isLayoutSuccessor(const MachineBasicBlock *MBB) const { @@ -533,13 +643,10 @@ bool MachineBasicBlock::canFallThrough() { 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 - // is possible. The isPredicable check is needed because this code can be + // is possible. The isPredicated check is needed because this code can be // called during IfConversion, where an instruction which is normally a - // Barrier is predicated and thus no longer an actual control barrier. This - // is over-conservative though, because if an instruction isn't actually - // predicated we could still treat it like a barrier. - return empty() || !back().isBarrier() || - back().isPredicable(); + // Barrier is predicated and thus no longer an actual control barrier. + return empty() || !back().isBarrier() || TII->isPredicated(&back()); } // If there is no branch, control always falls through. @@ -562,9 +669,19 @@ bool MachineBasicBlock::canFallThrough() { MachineBasicBlock * 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; + 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 NULL; + // 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(); @@ -590,6 +707,13 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { << " -- 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. @@ -598,15 +722,16 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { // Collect a list of virtual registers killed by the terminators. SmallVector KilledRegs; if (LV) - for (insn_iterator I = getFirstInsnTerminator(), E = insn_end(); + 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->isUse() || !OI->isKill() || OI->isUndef()) + if (!OI->isReg() || OI->getReg() == 0 || + !OI->isUse() || !OI->isKill() || OI->isUndef()) continue; unsigned Reg = OI->getReg(); - if (TargetRegisterInfo::isVirtualRegister(Reg) && + if (TargetRegisterInfo::isPhysicalRegister(Reg) || LV->getVarInfo(Reg).removeKill(MI)) { KilledRegs.push_back(Reg); DEBUG(dbgs() << "Removing terminator kill: " << *MI); @@ -615,37 +740,93 @@ 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); + + 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 - for (MachineBasicBlock::insn_iterator - i = Succ->insn_begin(),e = Succ->insn_end(); i != e && i->isPHI(); ++i) + 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() == this) 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) + E = Succ->livein_end(); I != E; ++I) NMBB->addLiveIn(*I); // Update LiveVariables. + const TargetRegisterInfo *TRI = MF->getTarget().getRegisterInfo(); if (LV) { // Restore kills of virtual registers that were killed by the terminators. while (!KilledRegs.empty()) { unsigned Reg = KilledRegs.pop_back_val(); - for (insn_iterator I = insn_end(), E = insn_begin(); I != E;) { - if (!(--I)->addRegisterKilled(Reg, NULL, /* addIfNotFound= */ false)) + for (instr_iterator I = instr_end(), E = instr_begin(); I != E;) { + if (!(--I)->addRegisterKilled(Reg, TRI, /* addIfNotFound= */ false)) continue; - LV->getVarInfo(Reg).Kills.push_back(I); + if (TargetRegisterInfo::isVirtualRegister(Reg)) + LV->getVarInfo(Reg).Kills.push_back(I); DEBUG(dbgs() << "Restored terminator kill: " << *I); break; } @@ -654,6 +835,67 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { LV->addNewBlock(NMBB, this, Succ); } + 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 = + llvm::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)); + } + } + } + + 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); + } + } + + // Update all intervals for registers whose uses may have been modified by + // updateTerminator(). + LIS->repairIntervalsInRange(this, getFirstTerminator(), end(), UsedRegs); + } + if (MachineDominatorTree *MDT = P->getAnalysisIfAvailable()) { // Update dominator information. @@ -711,6 +953,44 @@ MachineBasicBlock::SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P) { return NMBB; } +/// 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. +} + +MachineBasicBlock::instr_iterator +MachineBasicBlock::erase(MachineBasicBlock::instr_iterator I) { + unbundleSingleMI(I); + return Insts.erase(I); +} + +MachineInstr *MachineBasicBlock::remove_instr(MachineInstr *MI) { + unbundleSingleMI(MI); + MI->clearFlag(MachineInstr::BundledPred); + MI->clearFlag(MachineInstr::BundledSucc); + return Insts.remove(MI); +} + +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); + } + return Insts.insert(I, MI); +} + /// removeFromParent - This method unlinks 'this' from the containing function, /// and returns it, but does not delete it. MachineBasicBlock *MachineBasicBlock::removeFromParent() { @@ -734,8 +1014,8 @@ void MachineBasicBlock::ReplaceUsesOfBlockWith(MachineBasicBlock *Old, MachineBasicBlock *New) { assert(Old != New && "Cannot replace self with self!"); - MachineBasicBlock::insn_iterator I = insn_end(); - while (I != insn_begin()) { + MachineBasicBlock::instr_iterator I = instr_end(); + while (I != instr_begin()) { --I; if (!I->isTerminator()) break; @@ -816,9 +1096,9 @@ bool MachineBasicBlock::CorrectExtraCFGEdges(MachineBasicBlock *DestA, /// findDebugLoc - find the next valid DebugLoc starting at MBBI, skipping /// any DBG_VALUE instructions. Return UnknownLoc if there is none. DebugLoc -MachineBasicBlock::findDebugLoc(insn_iterator MBBI) { +MachineBasicBlock::findDebugLoc(instr_iterator MBBI) { DebugLoc DL; - insn_iterator E = insn_end(); + instr_iterator E = instr_end(); if (MBBI == E) return DL; @@ -832,12 +1112,11 @@ MachineBasicBlock::findDebugLoc(insn_iterator MBBI) { /// getSuccWeight - Return weight of the edge from this block to MBB. /// -uint32_t MachineBasicBlock::getSuccWeight(MachineBasicBlock *succ) { +uint32_t MachineBasicBlock::getSuccWeight(const_succ_iterator Succ) const { if (Weights.empty()) return 0; - succ_iterator I = std::find(Successors.begin(), Successors.end(), succ); - return *getWeightIterator(I); + return *getWeightIterator(Succ); } /// getWeightIterator - Return wight iterator corresonding to the I successor @@ -850,6 +1129,93 @@ getWeightIterator(MachineBasicBlock::succ_iterator I) { return Weights.begin() + index; } +/// getWeightIterator - 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!"); + const size_t index = std::distance(Successors.begin(), I); + assert(index < Weights.size() && "Not a current successor!"); + return Weights.begin() + index; +} + +/// 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; +} + void llvm::WriteAsOperand(raw_ostream &OS, const MachineBasicBlock *MBB, bool t) { OS << "BB#" << MBB->getNumber();