Compiler-assisted generation of error-detecting parallel programs

Abstract

We have developed an automated a compile time approach to generating error-detecting parallel programs. The compiler is used to identify statements implementing affine transformations within the program and to automatically insert code for computing, manipulating, and comparing checksums in order to detect data errors at runtime. Statements which do not implement affine transformations are checked by duplication. Checksums are reused from one loop to the next if this is possible, rather than recomputing checksums for every statement. A global dataflow analysis is performed in order to determine points at which checksums need to be recomputed. We also use a novel method of specifying the data distributions of the check data using data distribution directives so that the computations on the original data, and the corresponding check computations are performed on different processors. Results on the time overhead and error coverage of the error detecting parallel programs over the original programs are presented on an Intel Paragon distributed memory multicomputer.