#include "llvm/CodeGen/MachineBasicBlock.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/IR/LeakDetector.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.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 <algorithm>
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;
}
/// 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 TargetMachine &TM = MF->getTarget();
+ const char *Prefix = TM.getDataLayout()->getPrivateGlobalPrefix();
+ CachedMCSymbol = Ctx.GetOrCreateSymbol(Twine(Prefix) + "BB" +
+ Twine(MF->getFunctionNumber()) +
+ "_" + Twine(getNumber()));
+ }
+
+ return CachedMCSymbol;
}
/// list, we update its parent pointer and add its operands from reg use/def
/// lists if appropriate.
void ilist_traits<MachineInstr>::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
/// list, we update its parent pointer and remove its operands from reg use/def
/// lists if appropriate.
void ilist_traits<MachineInstr>::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);
+ N->setParent(nullptr);
LeakDetector::addGarbageObject(N);
}
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.
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)
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 = ", "; }
}
}
+void MachineBasicBlock::printAsOperand(raw_ostream &OS, bool /*PrintType*/) {
+ OS << "BB#" << getNumber();
+}
+
void MachineBasicBlock::removeLiveIn(unsigned Reg) {
std::vector<unsigned>::iterator I =
std::find(LiveIns.begin(), LiveIns.end(), Reg);
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);
}
// 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<MachineOperand, 4> Cond;
DebugLoc dl; // FIXME: this is nowhere
bool B = TII->AnalyzeBranch(*this, TBB, FBB, Cond);
// 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) {
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;
// 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;
}
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);
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() {
return false;
// Analyze the branches, if any, at the end of the block.
- MachineBasicBlock *TBB = 0, *FBB = 0;
+ MachineBasicBlock *TBB = nullptr, *FBB = nullptr;
SmallVector<MachineOperand, 4> Cond;
const TargetInstrInfo *TII = getParent()->getTarget().getInstrInfo();
if (TII->AnalyzeBranch(*this, TBB, FBB, Cond)) {
}
// 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.
// Otherwise, if it is conditional and has no explicit false block, it falls
// through.
- return FBB == 0;
+ return FBB == nullptr;
}
MachineBasicBlock *
// 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;
+ MachineBasicBlock *TBB = nullptr, *FBB = nullptr;
SmallVector<MachineOperand, 4> 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
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<LiveIntervals>();
+ SlotIndexes *Indexes = P->getAnalysisIfAvailable<SlotIndexes>();
+ 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.
}
}
+ SmallVector<unsigned, 4> 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<MachineInstr*, 4> Terminators;
+ if (Indexes) {
+ for (instr_iterator I = getFirstInstrTerminator(), E = instr_end();
+ I != E; ++I)
+ Terminators.push_back(I);
+ }
+
updateTerminator();
+ if (Indexes) {
+ SmallVector<MachineInstr*, 4> NewTerminators;
+ for (instr_iterator I = getFirstInstrTerminator(), E = instr_end();
+ I != E; ++I)
+ NewTerminators.push_back(I);
+
+ for (SmallVectorImpl<MachineInstr*>::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->getTarget().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
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 =
+ 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<unsigned, 8> 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<MachineDominatorTree>()) {
// Update dominator information.
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;
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::
// 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();
-}
-
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