remove dup check

Author: broxigarchen

llvm/lib/Target/AMDGPU/SIInstrInfo.cpp

@@ -8716,7 +8716,6 @@ void SIInstrInfo::splitScalar64BitCountOp(SIInstrWorklist &Worklist,
 void SIInstrInfo::addUsersToMoveToVALUWorklist(
     Register DstReg, MachineRegisterInfo &MRI,
     SIInstrWorklist &Worklist) const {
-  MachineInstr *prevMI = nullptr;
   for (MachineOperand &MO : make_early_inc_range(MRI.use_operands(DstReg))) {
     MachineInstr &UseMI = *MO.getParent();
 
@@ -8738,11 +8737,6 @@ void SIInstrInfo::addUsersToMoveToVALUWorklist(
     }
 
     if (!RI.hasVectorRegisters(getOpRegClass(UseMI, OpNo))) {
-      if (&UseMI == prevMI)
-        continue;
-
-      prevMI = &UseMI;
-
       Worklist.insert(&UseMI);
     } else {
       // legalize could changes user list