#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/ModuleSlotTracker.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
+#include "llvm/Support/DataTypes.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 <algorithm>
using namespace llvm;
-MachineBasicBlock::MachineBasicBlock(MachineFunction &mf, const BasicBlock *bb)
- : BB(bb), Number(-1), xParent(&mf), Alignment(0), IsLandingPad(false),
- AddressTaken(false), CachedMCSymbol(NULL) {
+#define DEBUG_TYPE "codegen"
+
+MachineBasicBlock::MachineBasicBlock(MachineFunction &MF, const BasicBlock *B)
+ : BB(B), Number(-1), xParent(&MF) {
Insts.Parent = this;
}
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 char *Prefix = Ctx.getAsmInfo().getPrivateGlobalPrefix();
- CachedMCSymbol = Ctx.GetOrCreateSymbol(Twine(Prefix) + "BB" +
+ const char *Prefix = Ctx.getAsmInfo()->getPrivateLabelPrefix();
+ assert(getNumber() >= 0 && "cannot get label for unreachable MBB");
+ CachedMCSymbol = Ctx.getOrCreateSymbol(Twine(Prefix) + "BB" +
Twine(MF->getFunctionNumber()) +
"_" + Twine(getNumber()));
}
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
for (MachineBasicBlock::instr_iterator
I = N->instr_begin(), E = N->instr_end(); I != E; ++I)
I->AddRegOperandsToUseLists(RegInfo);
-
- LeakDetector::removeGarbageObject(N);
}
void ilist_traits<MachineBasicBlock>::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<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
// 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<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);
-
- LeakDetector::addGarbageObject(N);
+ N->setParent(nullptr);
}
-/// 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<MachineInstr>::
-transferNodesFromList(ilist_traits<MachineInstr> &fromList,
- ilist_iterator<MachineInstr> first,
- ilist_iterator<MachineInstr> last) {
- assert(Parent->getParent() == fromList.Parent->getParent() &&
+transferNodesFromList(ilist_traits<MachineInstr> &FromList,
+ ilist_iterator<MachineInstr> First,
+ ilist_iterator<MachineInstr> Last) {
+ assert(Parent->getParent() == FromList.Parent->getParent() &&
"MachineInstr parent mismatch!");
// Splice within the same MBB -> no change.
- if (Parent == fromList.Parent) return;
+ if (Parent == FromList.Parent) return;
// If splicing between two blocks within the same function, just update the
// parent pointers.
- for (; first != last; ++first)
- first->setParent(Parent);
+ for (; First != Last; ++First)
+ First->setParent(Parent);
}
void ilist_traits<MachineInstr>::deleteNode(MachineInstr* MI) {
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.
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())
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;
}
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)
- return 0;
+ return nullptr;
for (const_succ_iterator I = succ_begin(), E = succ_end(); I != E; ++I)
- if ((*I)->isLandingPad())
+ if ((*I)->isEHPad())
return *I;
- return 0;
+ return nullptr;
+}
+
+bool MachineBasicBlock::hasEHPadSuccessor() const {
+ for (const_succ_iterator I = succ_begin(), E = succ_end(); I != E; ++I)
+ if ((*I)->isEHPad())
+ return true;
+ return false;
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
if (getBasicBlock())
Name += getBasicBlock()->getName();
else
- Name += (Twine("BB") + Twine(getNumber())).str();
+ Name += ("BB" + Twine(getNumber())).str();
return Name;
}
<< " 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';
const char *Comma = "";
if (const BasicBlock *LBB = getBasicBlock()) {
OS << Comma << "derived from LLVM BB ";
- WriteAsOperand(OS, LBB, /*PrintType=*/false);
+ LBB->printAsOperand(OS, /*PrintType=*/false, MST);
Comma = ", ";
}
- if (isLandingPad()) { OS << Comma << "EH LANDING PAD"; Comma = ", "; }
+ if (isEHPad()) { OS << Comma << "EH LANDING PAD"; Comma = ", "; }
if (hasAddressTaken()) { OS << Comma << "ADDRESS TAKEN"; Comma = ", "; }
if (Alignment)
OS << Comma << "Align " << Alignment << " (" << (1u << Alignment)
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 (const auto &LI : make_range(livein_begin(), livein_end())) {
+ OS << ' ' << PrintReg(LI.PhysReg, TRI);
+ if (LI.LaneMask != ~0u)
+ OS << ':' << PrintLaneMask(LI.LaneMask);
+ }
OS << '\n';
}
// Print the preds of this block according to the CFG.
for (const_instr_iterator I = instr_begin(); I != instr_end(); ++I) {
if (Indexes) {
- if (Indexes->hasIndex(I))
- OS << Indexes->getInstructionIndex(I);
+ if (Indexes->hasIndex(&*I))
+ OS << Indexes->getInstructionIndex(&*I);
OS << '\t';
}
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.
OS << " Successors according to CFG:";
for (const_succ_iterator SI = succ_begin(), E = succ_end(); SI != E; ++SI) {
OS << " BB#" << (*SI)->getNumber();
- if (!Weights.empty())
- OS << '(' << *getWeightIterator(SI) << ')';
+ if (!Probs.empty())
+ OS << '(' << *getProbabilityIterator(SI) << ')';
}
OS << '\n';
}
}
-void MachineBasicBlock::removeLiveIn(unsigned Reg) {
- std::vector<unsigned>::iterator I =
- std::find(LiveIns.begin(), LiveIns.end(), Reg);
- if (I != LiveIns.end())
+void MachineBasicBlock::printAsOperand(raw_ostream &OS,
+ bool /*PrintType*/) const {
+ OS << "BB#" << getNumber();
+}
+
+void MachineBasicBlock::removeLiveIn(MCPhysReg Reg, LaneBitmask LaneMask) {
+ LiveInVector::iterator I = std::find_if(
+ LiveIns.begin(), LiveIns.end(),
+ [Reg] (const RegisterMaskPair &LI) { return LI.PhysReg == Reg; });
+ if (I == LiveIns.end())
+ return;
+
+ I->LaneMask &= ~LaneMask;
+ if (I->LaneMask == 0)
LiveIns.erase(I);
}
-bool MachineBasicBlock::isLiveIn(unsigned Reg) const {
- livein_iterator I = std::find(livein_begin(), livein_end(), Reg);
- return I != livein_end();
+bool MachineBasicBlock::isLiveIn(MCPhysReg Reg, LaneBitmask LaneMask) const {
+ livein_iterator I = std::find_if(
+ LiveIns.begin(), LiveIns.end(),
+ [Reg] (const RegisterMaskPair &LI) { return LI.PhysReg == Reg; });
+ return I != livein_end() && (I->LaneMask & LaneMask) != 0;
+}
+
+void MachineBasicBlock::sortUniqueLiveIns() {
+ std::sort(LiveIns.begin(), LiveIns.end(),
+ [](const RegisterMaskPair &LI0, const RegisterMaskPair &LI1) {
+ return LI0.PhysReg < LI1.PhysReg;
+ });
+ // Liveins are sorted by physreg now we can merge their lanemasks.
+ LiveInVector::const_iterator I = LiveIns.begin();
+ LiveInVector::const_iterator J;
+ LiveInVector::iterator Out = LiveIns.begin();
+ for (; I != LiveIns.end(); ++Out, I = J) {
+ unsigned PhysReg = I->PhysReg;
+ LaneBitmask LaneMask = I->LaneMask;
+ for (J = std::next(I); J != LiveIns.end() && J->PhysReg == PhysReg; ++J)
+ LaneMask |= J->LaneMask;
+ Out->PhysReg = PhysReg;
+ Out->LaneMask = LaneMask;
+ }
+ LiveIns.erase(Out, LiveIns.end());
+}
+
+unsigned
+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");
+ assert((isEHPad() || 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);
+ getParent()->splice(NewAfter->getIterator(), getIterator());
}
void MachineBasicBlock::moveAfter(MachineBasicBlock *NewBefore) {
- MachineFunction::iterator BBI = NewBefore;
- getParent()->splice(++BBI, this);
+ getParent()->splice(++NewBefore->getIterator(), getIterator());
}
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<MachineOperand, 4> Cond;
- DebugLoc dl; // FIXME: this is nowhere
+ DebugLoc DL; // FIXME: this is nowhere
bool B = TII->AnalyzeBranch(*this, TBB, FBB, Cond);
(void) B;
assert(!B && "UpdateTerminators requires analyzable predecessors!");
// its layout successor, insert a branch. First we have to locate the
// only non-landing-pad successor, as that is the fallthrough block.
for (succ_iterator SI = succ_begin(), SE = succ_end(); SI != SE; ++SI) {
- if ((*SI)->isLandingPad())
+ if ((*SI)->isEHPad())
continue;
assert(!TBB && "Found more than one non-landing-pad successor!");
TBB = *SI;
// 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)
+ if ((*SI)->isEHPad() || *SI == TBB)
continue;
assert(!FallthroughBB && "Found more than one fallthrough successor.");
FallthroughBB = *SI;
// 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
// 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);
+ TII->InsertBranch(*this, TBB, FallthroughBB, Cond, DL);
}
}
}
}
-void MachineBasicBlock::addSuccessor(MachineBasicBlock *succ, uint32_t weight) {
-
- // If we see non-zero value for the first time it means we actually use Weight
- // list, so we fill all Weights with 0's.
- if (weight != 0 && Weights.empty())
- Weights.resize(Successors.size());
-
- if (weight != 0 || !Weights.empty())
- Weights.push_back(weight);
-
- Successors.push_back(succ);
- succ->addPredecessor(this);
- }
+void MachineBasicBlock::validateSuccProbs() const {
+#ifndef NDEBUG
+ int64_t Sum = 0;
+ for (auto Prob : Probs)
+ Sum += Prob.getNumerator();
+ // Due to precision issue, we assume that the sum of probabilities is one if
+ // the difference between the sum of their numerators and the denominator is
+ // no greater than the number of successors.
+ assert((uint64_t)std::abs(Sum - BranchProbability::getDenominator()) <=
+ Probs.size() &&
+ "The sum of successors's probabilities exceeds one.");
+#endif // NDEBUG
+}
-void MachineBasicBlock::removeSuccessor(MachineBasicBlock *succ) {
- succ->removePredecessor(this);
- succ_iterator I = std::find(Successors.begin(), Successors.end(), succ);
- assert(I != Successors.end() && "Not a current successor!");
+void MachineBasicBlock::addSuccessor(MachineBasicBlock *Succ,
+ BranchProbability Prob) {
+ // Probability list is either empty (if successor list isn't empty, this means
+ // disabled optimization) or has the same size as successor list.
+ if (!(Probs.empty() && !Successors.empty()))
+ Probs.push_back(Prob);
+ Successors.push_back(Succ);
+ Succ->addPredecessor(this);
+}
- // If Weight list is empty it means we don't use it (disabled optimization).
- if (!Weights.empty()) {
- weight_iterator WI = getWeightIterator(I);
- Weights.erase(WI);
- }
+void MachineBasicBlock::addSuccessorWithoutProb(MachineBasicBlock *Succ) {
+ // We need to make sure probability list is either empty or has the same size
+ // of successor list. When this function is called, we can safely delete all
+ // probability in the list.
+ Probs.clear();
+ Successors.push_back(Succ);
+ Succ->addPredecessor(this);
+}
- Successors.erase(I);
+void MachineBasicBlock::removeSuccessor(MachineBasicBlock *Succ,
+ bool NormalizeSuccProbs) {
+ succ_iterator I = std::find(Successors.begin(), Successors.end(), Succ);
+ removeSuccessor(I, NormalizeSuccProbs);
}
MachineBasicBlock::succ_iterator
-MachineBasicBlock::removeSuccessor(succ_iterator I) {
+MachineBasicBlock::removeSuccessor(succ_iterator I, bool NormalizeSuccProbs) {
assert(I != Successors.end() && "Not a current successor!");
- // If Weight list is empty it means we don't use it (disabled optimization).
- if (!Weights.empty()) {
- weight_iterator WI = getWeightIterator(I);
- Weights.erase(WI);
+ // If probability list is empty it means we don't use it (disabled
+ // optimization).
+ if (!Probs.empty()) {
+ probability_iterator WI = getProbabilityIterator(I);
+ Probs.erase(WI);
+ if (NormalizeSuccProbs)
+ normalizeSuccProbs();
}
(*I)->removePredecessor(this);
}
}
assert(OldI != E && "Old is not a successor of this block");
- Old->removePredecessor(this);
// If New isn't already a successor, let it take Old's place.
if (NewI == E) {
+ Old->removePredecessor(this);
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);
+ // Update its probability instead of adding a duplicate edge.
+ if (!Probs.empty()) {
+ auto ProbIter = getProbabilityIterator(NewI);
+ if (!ProbIter->isUnknown())
+ *ProbIter += *getProbabilityIterator(OldI);
}
- Successors.erase(OldI);
+ removeSuccessor(OldI);
}
-void MachineBasicBlock::addPredecessor(MachineBasicBlock *pred) {
- Predecessors.push_back(pred);
+void MachineBasicBlock::addPredecessor(MachineBasicBlock *Pred) {
+ Predecessors.push_back(Pred);
}
-void MachineBasicBlock::removePredecessor(MachineBasicBlock *pred) {
- pred_iterator I = std::find(Predecessors.begin(), Predecessors.end(), pred);
+void MachineBasicBlock::removePredecessor(MachineBasicBlock *Pred) {
+ pred_iterator I = std::find(Predecessors.begin(), Predecessors.end(), Pred);
assert(I != Predecessors.end() && "Pred is not a predecessor of this block!");
Predecessors.erase(I);
}
-void MachineBasicBlock::transferSuccessors(MachineBasicBlock *fromMBB) {
- if (this == fromMBB)
+void MachineBasicBlock::transferSuccessors(MachineBasicBlock *FromMBB) {
+ if (this == FromMBB)
return;
- while (!fromMBB->succ_empty()) {
- MachineBasicBlock *Succ = *fromMBB->succ_begin();
- uint32_t Weight = 0;
+ while (!FromMBB->succ_empty()) {
+ MachineBasicBlock *Succ = *FromMBB->succ_begin();
- // If Weight list is empty it means we don't use it (disabled optimization).
- if (!fromMBB->Weights.empty())
- Weight = *fromMBB->Weights.begin();
+ // If probability list is empty it means we don't use it (disabled optimization).
+ if (!FromMBB->Probs.empty()) {
+ auto Prob = *FromMBB->Probs.begin();
+ addSuccessor(Succ, Prob);
+ } else
+ addSuccessorWithoutProb(Succ);
- addSuccessor(Succ, Weight);
- fromMBB->removeSuccessor(Succ);
+ FromMBB->removeSuccessor(Succ);
}
}
void
-MachineBasicBlock::transferSuccessorsAndUpdatePHIs(MachineBasicBlock *fromMBB) {
- if (this == fromMBB)
+MachineBasicBlock::transferSuccessorsAndUpdatePHIs(MachineBasicBlock *FromMBB) {
+ if (this == FromMBB)
return;
- while (!fromMBB->succ_empty()) {
- MachineBasicBlock *Succ = *fromMBB->succ_begin();
- uint32_t Weight = 0;
- if (!fromMBB->Weights.empty())
- Weight = *fromMBB->Weights.begin();
- addSuccessor(Succ, Weight);
- fromMBB->removeSuccessor(Succ);
+ while (!FromMBB->succ_empty()) {
+ MachineBasicBlock *Succ = *FromMBB->succ_begin();
+ if (!FromMBB->Probs.empty()) {
+ auto Prob = *FromMBB->Probs.begin();
+ addSuccessor(Succ, Prob);
+ } else
+ addSuccessorWithoutProb(Succ);
+ FromMBB->removeSuccessor(Succ);
// Fix up any PHI nodes in the successor.
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)
+ if (MO.getMBB() == FromMBB)
MO.setMBB(this);
}
}
+ normalizeSuccProbs();
}
bool MachineBasicBlock::isPredecessor(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() {
- MachineFunction::iterator Fallthrough = this;
+ MachineFunction::iterator Fallthrough = getIterator();
++Fallthrough;
// If FallthroughBlock is off the end of the function, it can't fall through.
if (Fallthrough == getParent()->end())
return false;
// If FallthroughBlock isn't a successor, no fallthrough is possible.
- if (!isSuccessor(Fallthrough))
+ if (!isSuccessor(&*Fallthrough))
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();
+ 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
}
// 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 *
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;
+ if (Succ->isEHPad())
+ return nullptr;
MachineFunction *MF = getParent();
- DebugLoc dl; // FIXME: this is nowhere
+ 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<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()
if (LV)
for (instr_iterator I = getFirstInstrTerminator(), E = instr_end();
I != E; ++I) {
- MachineInstr *MI = 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 ||
if (LIS) {
for (instr_iterator I = getFirstInstrTerminator(), E = instr_end();
I != E; ++I) {
- MachineInstr *MI = I;
+ MachineInstr *MI = &*I;
for (MachineInstr::mop_iterator OI = MI->operands_begin(),
OE = MI->operands_end(); OI != OE; ++OI) {
if (Indexes) {
for (instr_iterator I = getFirstInstrTerminator(), E = instr_end();
I != E; ++I)
- Terminators.push_back(I);
+ Terminators.push_back(&*I);
}
updateTerminator();
SmallVector<MachineInstr*, 4> NewTerminators;
for (instr_iterator I = getFirstInstrTerminator(), E = instr_end();
I != E; ++I)
- NewTerminators.push_back(I);
+ NewTerminators.push_back(&*I);
for (SmallVectorImpl<MachineInstr*>::iterator I = Terminators.begin(),
E = Terminators.end(); I != E; ++I) {
NMBB->addSuccessor(Succ);
if (!NMBB->isLayoutSuccessor(Succ)) {
Cond.clear();
- MF->getTarget().getInstrInfo()->InsertBranch(*NMBB, Succ, NULL, Cond, dl);
+ TII->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);
+ if (Indexes->hasIndex(&*I))
+ Indexes->removeMachineInstrFromMaps(&*I);
+ Indexes->insertMachineInstrInMaps(&*I);
}
}
}
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 (const auto &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()) {
if (!(--I)->addRegisterKilled(Reg, TRI, /* addIfNotFound= */ false))
continue;
if (TargetRegisterInfo::isVirtualRegister(Reg))
- LV->getVarInfo(Reg).Kills.push_back(I);
+ LV->getVarInfo(Reg).Kills.push_back(&*I);
DEBUG(dbgs() << "Restored terminator kill: " << *I);
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.
+ // 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();
+ std::next(MachineFunction::iterator(NMBB)) == getParent()->end();
SlotIndex StartIndex = Indexes->getMBBEndIdx(this);
SlotIndex PrevIndex = StartIndex.getPrevSlot();
LiveInterval &LI = LIS->getInterval(Reg);
VNInfo *VNI = LI.getVNInfoAt(PrevIndex);
- assert(VNI && "PHI sources should be live out of their predecessors.");
- LI.addRange(LiveRange(StartIndex, EndIndex, VNI));
+ assert(VNI &&
+ "PHI sources should be live out of their predecessors.");
+ LI.addSegment(LiveInterval::Segment(StartIndex, EndIndex, VNI));
}
}
}
if (isLiveOut && isLastMBB) {
VNInfo *VNI = LI.getVNInfoAt(PrevIndex);
assert(VNI && "LiveInterval should have VNInfo where it is live.");
- LI.addRange(LiveRange(StartIndex, EndIndex, VNI));
+ LI.addSegment(LiveInterval::Segment(StartIndex, EndIndex, VNI));
} else if (!isLiveOut && !isLastMBB) {
- LI.removeRange(StartIndex, EndIndex);
+ LI.removeSegment(StartIndex, EndIndex);
}
}
}
if (MachineDominatorTree *MDT =
- P->getAnalysisIfAvailable<MachineDominatorTree>()) {
- // 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<MachineDominatorTree>())
+ MDT->recordSplitCriticalEdge(this, Succ, NMBB);
if (MachineLoopInfo *MLI = P->getAnalysisIfAvailable<MachineLoopInfo>())
if (MachineLoop *TIL = MLI->getLoopFor(this)) {
MachineBasicBlock::instr_iterator
MachineBasicBlock::erase(MachineBasicBlock::instr_iterator I) {
- unbundleSingleMI(I);
+ unbundleSingleMI(&*I);
return Insts.erase(I);
}
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!");
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).
/// Note it is possible that DestA and/or DestB are LandingPads.
bool MachineBasicBlock::CorrectExtraCFGEdges(MachineBasicBlock *DestA,
MachineBasicBlock *DestB,
- bool isCond) {
+ bool IsCond) {
// The values of DestA and DestB frequently come from a call to the
// 'TargetInstrInfo::AnalyzeBranch' method. We take our meaning of the initial
// values from there.
//
// 1. If both DestA and DestB are null, then the block ends with no branches
// (it falls through to its successor).
- // 2. If DestA is set, DestB is null, and isCond is false, then the block ends
+ // 2. If DestA is set, DestB is null, and IsCond is false, then the block ends
// with only an unconditional branch.
- // 3. If DestA is set, DestB is null, and isCond is true, then the block ends
+ // 3. If DestA is set, DestB is null, and IsCond is true, then the block ends
// with a conditional branch that falls through to a successor (DestB).
- // 4. If DestA and DestB is set and isCond is true, then the block ends with a
+ // 4. If DestA and DestB is set and IsCond is true, then the block ends with a
// conditional branch followed by an unconditional branch. DestA is the
// 'true' destination and DestB is the 'false' destination.
bool Changed = false;
- MachineFunction::iterator FallThru =
- llvm::next(MachineFunction::iterator(this));
+ MachineFunction::iterator FallThru = std::next(getIterator());
- if (DestA == 0 && DestB == 0) {
+ if (!DestA && !DestB) {
// Block falls through to successor.
- DestA = FallThru;
- DestB = FallThru;
- } else if (DestA != 0 && DestB == 0) {
- if (isCond)
+ DestA = &*FallThru;
+ DestB = &*FallThru;
+ } else if (DestA && !DestB) {
+ if (IsCond)
// Block ends in conditional jump that falls through to successor.
- DestB = FallThru;
+ DestB = &*FallThru;
} else {
- assert(DestA && DestB && isCond &&
+ assert(DestA && DestB && IsCond &&
"CFG in a bad state. Cannot correct CFG edges");
}
MachineBasicBlock::succ_iterator SI = succ_begin();
while (SI != succ_end()) {
const MachineBasicBlock *MBB = *SI;
- if (!SeenMBBs.insert(MBB) ||
- (MBB != DestA && MBB != DestB && !MBB->isLandingPad())) {
+ if (!SeenMBBs.insert(MBB).second ||
+ (MBB != DestA && MBB != DestB && !MBB->isEHPad())) {
// This is a superfluous edge, remove it.
SI = removeSuccessor(SI);
Changed = true;
}
}
+ if (Changed)
+ normalizeSuccProbs();
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;
return DL;
}
-/// getSuccWeight - Return weight of the edge from this block to MBB.
-///
-uint32_t MachineBasicBlock::getSuccWeight(const_succ_iterator Succ) const {
- if (Weights.empty())
- return 0;
+/// Return probability of the edge from this block to MBB.
+BranchProbability
+MachineBasicBlock::getSuccProbability(const_succ_iterator Succ) const {
+ if (Probs.empty())
+ return BranchProbability(1, succ_size());
+
+ const auto &Prob = *getProbabilityIterator(Succ);
+ if (Prob.isUnknown()) {
+ // For unknown probabilities, collect the sum of all known ones, and evenly
+ // ditribute the complemental of the sum to each unknown probability.
+ unsigned KnownProbNum = 0;
+ auto Sum = BranchProbability::getZero();
+ for (auto &P : Probs) {
+ if (!P.isUnknown()) {
+ Sum += P;
+ KnownProbNum++;
+ }
+ }
+ return Sum.getCompl() / (Probs.size() - KnownProbNum);
+ } else
+ return Prob;
+}
- return *getWeightIterator(Succ);
+/// Set successor probability of a given iterator.
+void MachineBasicBlock::setSuccProbability(succ_iterator I,
+ BranchProbability Prob) {
+ assert(!Prob.isUnknown());
+ if (Probs.empty())
+ return;
+ *getProbabilityIterator(I) = Prob;
}
-/// getWeightIterator - 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!");
- size_t index = std::distance(Successors.begin(), I);
- assert(index < Weights.size() && "Not a current successor!");
- return Weights.begin() + index;
+/// Return probability iterator corresonding to the I successor iterator
+MachineBasicBlock::const_probability_iterator
+MachineBasicBlock::getProbabilityIterator(
+ MachineBasicBlock::const_succ_iterator I) const {
+ assert(Probs.size() == Successors.size() && "Async probability list!");
+ const size_t index = std::distance(Successors.begin(), I);
+ assert(index < Probs.size() && "Not a current successor!");
+ return Probs.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!");
+/// Return probability iterator corresonding to the I successor iterator.
+MachineBasicBlock::probability_iterator
+MachineBasicBlock::getProbabilityIterator(MachineBasicBlock::succ_iterator I) {
+ assert(Probs.size() == Successors.size() && "Async probability list!");
const size_t index = std::distance(Successors.begin(), I);
- assert(index < Weights.size() && "Not a current successor!");
- return Weights.begin() + index;
+ assert(index < Probs.size() && "Not a current successor!");
+ return Probs.begin() + index;
}
/// Return whether (physical) register "Reg" has been <def>ined and not <kill>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 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);
+ MachineOperandIteratorBase::PhysRegInfo Info =
+ ConstMIOperands(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;
+ // Defs happen after uses so they take precedence if both are present.
- if (Analysis.Kills || Analysis.Clobbers)
- // Register killed, so isn't live.
+ // Register is dead after a dead def of the full register.
+ if (Info.DeadDef)
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);
+ // Register is (at least partially) live after a def.
+ if (Info.Defined)
+ return LQR_Live;
+ // Register is dead after a full kill or clobber and no def.
+ if (Info.Killed || Info.Clobbered)
+ return LQR_Dead;
+ // Register must be live if we read it.
+ if (Info.Read)
+ return LQR_Live;
+ } 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))
- return (*RAI == Reg) ? LQR_Live : LQR_OverlappingLive;
- }
+ for (MCRegAliasIterator RAI(Reg, TRI, /*IncludeSelf=*/true); RAI.isValid();
+ ++RAI)
+ if (isLiveIn(*RAI))
+ return LQR_Live;
return LQR_Dead;
}
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) {
- 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.
+ if (I != end()) {
+ for (++I; I != end() && N > 0; ++I, --N) {
+ MachineOperandIteratorBase::PhysRegInfo Info =
+ ConstMIOperands(I).analyzePhysReg(Reg, TRI);
+
+ // Register is live when we read it here.
+ if (Info.Read)
+ return LQR_Live;
+ // Register is dead if we can fully overwrite or clobber it here.
+ if (Info.FullyDefined || Info.Clobbered)
return LQR_Dead;
}
}
return LQR_Unknown;
}
-void llvm::WriteAsOperand(raw_ostream &OS, const MachineBasicBlock *MBB,
- bool t) {
- OS << "BB#" << MBB->getNumber();
+const uint32_t *
+MachineBasicBlock::getBeginClobberMask(const TargetRegisterInfo *TRI) const {
+ // EH funclet entry does not preserve any registers.
+ return isEHFuncletEntry() ? TRI->getNoPreservedMask() : nullptr;
}
+const uint32_t *
+MachineBasicBlock::getEndClobberMask(const TargetRegisterInfo *TRI) const {
+ // If we see a return block with successors, this must be a funclet return,
+ // which does not preserve any registers. If there are no successors, we don't
+ // care what kind of return it is, putting a mask after it is a no-op.
+ return isReturnBlock() && !succ_empty() ? TRI->getNoPreservedMask() : nullptr;
+}