// Find all the values used, including PHI kills.
SmallVector<std::pair<SlotIndex, VNInfo*>, 16> WorkList;
+ // Blocks that have already been added to WorkList as live-out.
+ SmallPtrSet<MachineBasicBlock*, 16> LiveOut;
+
// Visit all instructions reading li->reg.
for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(li->reg);
MachineInstr *UseMI = I.skipInstruction();) {
VNInfo *VNI = *I;
if (VNI->isUnused())
continue;
- // We may eliminate PHI values, so recompute PHIKill flags.
- VNI->setHasPHIKill(false);
NewLI.addRange(LiveRange(VNI->def, VNI->def.getNextSlot(), VNI));
// A use tied to an early-clobber def ends at the load slot and isn't caught
// The PHI is live, make sure the predecessors are live-out.
for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(),
PE = MBB->pred_end(); PI != PE; ++PI) {
+ if (!LiveOut.insert(*PI))
+ continue;
SlotIndex Stop = getMBBEndIdx(*PI).getPrevSlot();
- VNInfo *PVNI = li->getVNInfoAt(Stop);
// A predecessor is not required to have a live-out value for a PHI.
- if (PVNI) {
- PVNI->setHasPHIKill(true);
+ if (VNInfo *PVNI = li->getVNInfoAt(Stop))
WorkList.push_back(std::make_pair(Stop, PVNI));
- }
}
continue;
}
// Make sure VNI is live-out from the predecessors.
for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(),
PE = MBB->pred_end(); PI != PE; ++PI) {
+ if (!LiveOut.insert(*PI))
+ continue;
SlotIndex Stop = getMBBEndIdx(*PI).getPrevSlot();
assert(li->getVNInfoAt(Stop) == VNI && "Wrong value out of predecessor");
WorkList.push_back(std::make_pair(Stop, VNI));