Iteration Space Slicing and Its Application to Communication Optimization

Program slicing is an analysis that answers questions such as \Which statements might a ect the computation of variable v at statement s?" or \Which statements depend on the value of v computed in statement s?". The answers computed by program slicing are generally a set of statements. We introduce the idea of iteration spacing slicing: we re ne program slicing to ask questions such as \Which iterations of which statements might e ect the computation in iterations I of statement s?" or \Which iterations of which statements depend on the value computed by iterations I of statement s?". One application of this general-purpose technique is optimization of interprocessor communication in data-parallel compilers. For example, we can separate a code fragment into 1) those iterations that must be done before a send, 2) those iterations that don't need to be done before a send and don't depend on non-local data and 3), those iterations that depend on non-local da...

• Type: Conference
• Year: 1997
• Where: ICS
• Authors: William Pugh, Evan Rosser
• Keywords: Distributed And Parallel Computing, ICS 1997, Iteration, Program Slicing, Statement S