Interactive and symbolic data dependence analysis based on ranges of expressions

Traditional data dependence testing algorithms have become very accurate and efficient for simple subscript expressions, but they cannot handle symbolic expressions because of the complexity of data-flow and lack of the semantic information of variables in programs. In this paper, a range-based testing and query approach, called DDTQ, is proposed to eliminate data dependence between array references with symbolic subscripts. DDTQ firstly extracts data dependence information from the symbolic subscripts, a testing algorithm is then used to disprove the dependence based on the ranges of expressions. The assumed dependence that cannot be handled by the disprover will be converted into simple questions by a question engine so that the compiler can solve them by user interaction in a friendly way. The experiment on perfect benchmarks indicates that DDTQ is effective in improving the parallelizing capability of the compiler.