Martin Griebl

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The polytope model has been used successfully as a tool for program analysis and transformation in the field of automatic loop parallelization. However, for the final step of automatic code generation, the generated code is either only usable on shared memory architectures or severely restricts the parallelization methods that can be applied. In this paper,(More)
We report on a prototype for testing diierent methods of space-time mapping loop nests. LooPo admits perfect or imperfect loop nests in a number of imperative languages, takes data dependences from the user or derives them itself from the source code, provides a choice of strategies for scheduling and allocating the loop nest's iterations, and produces(More)
There are many algorithms for the space-time mapping of nested loops. Some of them even make the optimal choices within their framework. We propose a preprocessing phase for algorithms in the polytope model, which extends the model and yields space-time mappings whose schedule is, in some cases, orders of magnitude faster. These are cases in which the(More)
Automatic parallelization of imperative programs has focused on nests of do loops with aane bounds and aane dependences, because in this case execution domains and dependences are precisely known at compile-time. Parallelization can then be done using a suitable space-time transformation , yielding a logically synchronous program. Code generation consists(More)
We present an application of quantifier elimination techniques in the automatic parallelization of nested loop programs. The technical goal is to simplify affine inequalities whose coefficients may be unevaluated symbolic constants. The values of these so-called structure parameters are determined at run time and reflect the problem size. Our purpose here(More)