Undoing Code Transformations in an Independent Order
نویسندگان
چکیده
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.
منابع مشابه
Graphical visualization of compiler optimizations
This paper describes xvpodb, a visualization tool developed to support the analysis of optimizations performed by the vpo optimizer. The tool is a graphical optimization viewer that can display the state of the program representation before and after sequences of changes, referred to as transformations, that results in semantically equivalent (and usually improved) code. The information and ins...
متن کاملAn Efficient Technique to Remove Transformations
Although the application of code transformations is critical to exploit parallelism in program code, few guidelines or tools are provided to determine what transformations should be applied and where they should be applied. In this paper, we approach this problem by first providing a taxonomy of code transformations to assist the user in parallelizing programs. We then present an efficient tech...
متن کاملPotter ' s Wheel : An Interactive Framework for Data Cleaning and Transformation
Real world data often has discrepancies in structure and content. Traditional methods for \cleaning" the data involve many iterations of time-consuming \data quality" analysis to nd discrepancies, and long-running transformations to x them. This process requires users to endure long waits and often write complex transformation programs. We present an interactive framework for data cleaning that...
متن کاملAn Interactive Framework for Data Cleaning
Cleaning organizational data of discrepancies in structure and content is important for data warehousing and Enterprise Data Integration (EDI). Current commercial solutions for data cleaning involve many iterations of time-consuming “data quality” analysis to find errors, and long-running transformations to fix them. Users need to endure long waits and often write complex transformation program...
متن کاملDufour and Soret Effects on Unsteady Heat and Mass Transfer for Powell-Eyring Fluid Flow over an Expanding Permeable Sheet
In the present analysis, the Dufour and Soret effects on unsteady heat-mass transfer of a viscous incompressible Powell-Eyring fluids flow past an expanding/shrinking permeable sheet are reported. The fluid boundary layer develops over the variable sheet with suction/injection to the non-uniform free stream velocity. Under the symmetry group of transformations, the governing equations along wit...
متن کامل