+
+ // If the target knows how to save/restore the register, let it do so;
+ // otherwise, use the emergency stack spill slot.
+ if (!TRI->saveScavengerRegister(*MBB, I, UseMI, RC, SReg)) {
+ // Spill the scavenged register before I.
+ assert(ScavengingFrameIndex >= 0 &&
+ "Cannot scavenge register without an emergency spill slot!");
+ TII->storeRegToStackSlot(*MBB, I, SReg, true, ScavengingFrameIndex, RC,TRI);
+ MachineBasicBlock::iterator II = prior(I);
+ TRI->eliminateFrameIndex(II, SPAdj, this);
+
+ // Restore the scavenged register before its use (or first terminator).
+ TII->loadRegFromStackSlot(*MBB, UseMI, SReg, ScavengingFrameIndex, RC, TRI);
+ II = prior(UseMI);
+ TRI->eliminateFrameIndex(II, SPAdj, this);
+ }
+
+ ScavengeRestore = prior(UseMI);
+
+ // Doing this here leads to infinite regress.
+ // ScavengedReg = SReg;