diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp index 99090a8269d4..75288b0934cb 100644 --- a/llvm/lib/CodeGen/BranchFolding.cpp +++ b/llvm/lib/CodeGen/BranchFolding.cpp @@ -1624,26 +1624,29 @@ bool BranchFolder::HoistCommonCodeInSuccs(MachineBasicBlock *MBB) { if (!TIB->isSafeToMove(TII, 0, DontMoveAcrossStore)) break; + // Remove kills from LocalDefsSet, these registers had short live ranges. + for (unsigned i = 0, e = TIB->getNumOperands(); i != e; ++i) { + MachineOperand &MO = TIB->getOperand(i); + if (!MO.isReg() || !MO.isUse() || !MO.isKill()) + continue; + unsigned Reg = MO.getReg(); + if (!Reg || !LocalDefsSet.count(Reg)) + continue; + for (const unsigned *OR = TRI->getOverlaps(Reg); *OR; ++OR) + LocalDefsSet.erase(*OR); + } + // Track local defs so we can update liveins. for (unsigned i = 0, e = TIB->getNumOperands(); i != e; ++i) { MachineOperand &MO = TIB->getOperand(i); - if (!MO.isReg()) + if (!MO.isReg() || !MO.isDef() || MO.isDead()) continue; unsigned Reg = MO.getReg(); if (!Reg) continue; - if (MO.isDef()) { - if (!MO.isDead()) { - LocalDefs.push_back(Reg); - LocalDefsSet.insert(Reg); - for (const unsigned *SR = TRI->getSubRegisters(Reg); *SR; ++SR) - LocalDefsSet.insert(*SR); - } - } else if (MO.isKill() && LocalDefsSet.count(Reg)) { - LocalDefsSet.erase(Reg); - for (const unsigned *SR = TRI->getSubRegisters(Reg); *SR; ++SR) - LocalDefsSet.erase(*SR); - } + LocalDefs.push_back(Reg); + for (const unsigned *OR = TRI->getOverlaps(Reg); *OR; ++OR) + LocalDefsSet.insert(*OR); } HasDups = true;;