harpoon.Backend.Generic
Class RegFileInfo.SpillException

java.lang.Object
  java.lang.Throwable
      java.lang.Exception
          harpoon.Backend.Generic.RegFileInfo.SpillException

All Implemented Interfaces:

Serializable

Enclosing class:

RegFileInfo

public abstract static class RegFileInfo.SpillException
extends Exception

SpillException tells a register allocator which Temps are appropriate for spilling in order to allocate space for another Temp. In the common case, this.getPotentialSpills() will just return an Iterator that iterates through singleton Sets for all of the registers. It is the responsibility of the register allocator to actually decide which set of registers to spill, to generate the code to save the values within said registers to their appropriate memory locations, and to generate the code to put those values back in the register file when they are needed next.

See Also:

Serialized Form

Constructor Summary

RegFileInfo.SpillException()

RegFileInfo.SpillException(String s)

Method Summary

abstract Iterator

getPotentialSpills() Returns an iterator of spill candidates.

Methods inherited from class java.lang.Throwable

fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

RegFileInfo.SpillException

public RegFileInfo.SpillException()

RegFileInfo.SpillException

public RegFileInfo.SpillException(String s)

Method Detail

getPotentialSpills

public abstract Iterator getPotentialSpills()

Returns an iterator of spill candidates.
effects: Returns a Set Iterator of spill candidates. Each element of the Iterator returned represents a Set of Register Temps that could be spilled to free up the amount of space needed for the attempted assignment in the register file. The returned Iterator is not guaranteed to iterate through all possible Sets of combinations of spill candidates, but should iterate through a decent selection so that the Register Allocator has significant freedom in selecting registers to spill.