new warnings: possible use of uninitialized value?

I'm seeing the following warning when compiling LLVM trunk in a Release build:

  llvm/lib/CodeGen/PrologEpilogInserter.cpp: In member function ‘void llvm::PEI::scavengeFrameVirtualRegs(llvm::MachineFunction&)’:
  llvm/lib/CodeGen/PrologEpilogInserter.cpp:770: warning: ‘PrevValue’ may be used uninitialized in this function

I briefly looked at the code and it looks like PrevValue is used correctly, but there is enough logic here that I'm not familiar with that I could easily be mistaken.