need help on the code in RegAllocGreedy.cpp->tryAssign()

[BaoshanPang]

I am trying to understand this part of code:

568 │ // If we missed a simple hint, try to cheaply evict interference from the
  569 │ // preferred register.
  570 │ if (Register Hint = MRI->getSimpleHint(VirtReg.reg()))
  571 │ │ if (Order.isHint(Hint)) {
  572 │ │ │ MCRegister PhysHint = Hint.asMCReg();

The 'Hint' is always 'virtual register' as when it is set by setSimpleHint it's type is forced to be 'virtual':

847 │ Register getSimpleHint(Register VReg) const {
  848 │ │ assert(VReg.isVirtual());
  849 │ │ std::pair<unsigned, Register> Hint = getRegAllocationHint(VReg);
  850 │ │ return Hint.first ? Register() : Hint.second;
  851 │ }

But the function "Order.isHint" would only return true when 'Hint' is phsical register:

 113 │ /// Return true if Reg is a preferred physical register.
  114 │ bool isHint(Register Reg) const {
  115 │ │ assert(!Reg.isPhysical() ||
  116 │ │ │ │ │ │Reg.id() <
  117 │ │ │ │ │ │ │ │static_cast<uint32_t>(std::numeric_limits<MCPhysReg>::max()));
  118 │ │ return Reg.isPhysical() && is_contained(Hints, Reg.id());
  119 │ }

How this code can works? isn't the code dead actually?