Explicit data placement (XDP): A methodology for explicit compile-time representation and optimization of data movement

The ability to represent, manipulate and optimize data movement between devices such as processors in a distributed memory machine, or between global memory and processors in a shared memory machine, is crucial in generating efficient code for such machines. In this paper we describe a methodology for representing and manipulating data movement explicitly in a compiler. Our methodology, called Explicit Data Placement (XDP), consists of extensions to the compiler's intermediate program language, as well as run-time structures that allow certain operations to be performed efficiently. We also illustrate one of the unique features of the XDP methodology: the ability to manipulate the run-time transfer of data ownership between processors.