+/* This function will do the following:
+ - If MBB is an entry or exit block, set SR1 and SR2 to R0 and R12
+ respectively (defaults recommended by the ABI) and return true
+ - If MBB is not an entry block, initialize the register scavenger and look
+ for available registers.
+ - If the defaults (R0/R12) are available, return true
+ - If TwoUniqueRegsRequired is set to true, it looks for two unique
+ registers. Otherwise, look for a single available register.
+ - If the required registers are found, set SR1 and SR2 and return true.
+ - If the required registers are not found, set SR2 or both SR1 and SR2 to
+ PPC::NoRegister and return false.
+
+ Note that if both SR1 and SR2 are valid parameters and TwoUniqueRegsRequired
+ is not set, this function will attempt to find two different registers, but
+ still return true if only one register is available (and set SR1 == SR2).
+*/
+bool
+PPCFrameLowering::findScratchRegister(MachineBasicBlock *MBB,
+ bool UseAtEnd,
+ bool TwoUniqueRegsRequired,
+ unsigned *SR1,
+ unsigned *SR2) const {