<li><tt>getCalleeSavedRegs</tt> — Returns a list of callee-saved registers
in the order of the desired callee-save stack frame offset.</li>
-<li><tt>getCalleeSavedRegClasses</tt> — Returns a list of preferred
- register classes with which to spill each callee saved register.</li>
-
<li><tt>getReservedRegs</tt> — Returns a bitset indexed by physical
register numbers, indicating if a particular register is unavailable.</li>