Undoing Code Transformations in an Independent Order

A transformation applied to optimize or parallelize a program may be found to be ineffective, or may be made invalid by code changes. In this paper, we present a technique to remove such transformations. The order of undoing the transformations is independent of the application order. The technique uses post conditions of a transformation to determine whether the transformation can be immediately removed. Transformations that affect the immediate removal of a transformation must be identified and removed. Other transformations made invalid by the removal of a transformation must also be undone. The technique employs inverse primitive actions, making the technique transformation independent. The enabling and disabling interactions of transformations are used to drive the process, thereby reducing redundant analysis when undoing transformations.