- return true;
-}
-
-MachineBasicBlock *PHIElimination::SplitCriticalEdge(MachineBasicBlock *A,
- MachineBasicBlock *B) {
- assert(A && B && "Missing MBB end point");
-
- MachineFunction *MF = A->getParent();
-
- // We may need to update A's terminator, but we can't do that if AnalyzeBranch
- // fails. If A uses a jump table, we won't touch it.
- const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
- MachineBasicBlock *TBB = 0, *FBB = 0;
- SmallVector<MachineOperand, 4> Cond;
- if (TII->AnalyzeBranch(*A, TBB, FBB, Cond))
- return NULL;
-
- ++NumSplits;
-
- MachineBasicBlock *NMBB = MF->CreateMachineBasicBlock();
- MF->insert(llvm::next(MachineFunction::iterator(A)), NMBB);
- DEBUG(dbgs() << "PHIElimination splitting critical edge:"
- " BB#" << A->getNumber()
- << " -- BB#" << NMBB->getNumber()
- << " -- BB#" << B->getNumber() << '\n');
-
- A->ReplaceUsesOfBlockWith(B, NMBB);
- A->updateTerminator();
-
- // Insert unconditional "jump B" instruction in NMBB if necessary.
- NMBB->addSuccessor(B);
- if (!NMBB->isLayoutSuccessor(B)) {
- Cond.clear();
- MF->getTarget().getInstrInfo()->InsertBranch(*NMBB, B, NULL, Cond);
- }
-
- // Fix PHI nodes in B so they refer to NMBB instead of A
- for (MachineBasicBlock::iterator i = B->begin(), e = B->end();
- i != e && i->isPHI(); ++i)
- for (unsigned ni = 1, ne = i->getNumOperands(); ni != ne; ni += 2)
- if (i->getOperand(ni+1).getMBB() == A)
- i->getOperand(ni+1).setMBB(NMBB);
-
- if (LiveVariables *LV=getAnalysisIfAvailable<LiveVariables>())
- LV->addNewBlock(NMBB, A, B);
-
- if (MachineDominatorTree *MDT=getAnalysisIfAvailable<MachineDominatorTree>())
- MDT->addNewBlock(NMBB, A);
-
- return NMBB;
-}
-
-unsigned
-PHIElimination::PHINodeTraits::getHashValue(const MachineInstr *MI) {
- if (!MI || MI==getEmptyKey() || MI==getTombstoneKey())
- return DenseMapInfo<MachineInstr*>::getHashValue(MI);
- unsigned hash = 0;
- for (unsigned ni = 1, ne = MI->getNumOperands(); ni != ne; ni += 2)
- hash = hash*37 + DenseMapInfo<BBVRegPair>::
- getHashValue(BBVRegPair(MI->getOperand(ni+1).getMBB()->getNumber(),
- MI->getOperand(ni).getReg()));
- return hash;
-}
-
-bool PHIElimination::PHINodeTraits::isEqual(const MachineInstr *LHS,
- const MachineInstr *RHS) {
- const MachineInstr *EmptyKey = getEmptyKey();
- const MachineInstr *TombstoneKey = getTombstoneKey();
- if (!LHS || !RHS || LHS==EmptyKey || RHS==EmptyKey ||
- LHS==TombstoneKey || RHS==TombstoneKey)
- return LHS==RHS;
-
- unsigned ne = LHS->getNumOperands();
- if (ne != RHS->getNumOperands())
- return false;
- // Ignore operand 0, the defined register.
- for (unsigned ni = 1; ni != ne; ni += 2)
- if (LHS->getOperand(ni).getReg() != RHS->getOperand(ni).getReg() ||
- LHS->getOperand(ni+1).getMBB() != RHS->getOperand(ni+1).getMBB())
- return false;
- return true;