Precise and efficient dependence tests are essential to theeffectivermss ofaparallelizing compiler. This paper proposes a dependence testing scheme based on classifyingpairs ofsubscripted variable references. Exact yet fast dependence tests are presented for certain classes ofarray references, as well as empirical results showing that these references dominate scientific Fortran codes. These dependence tests are being implemented at Rice University in both PFC, aparallelizing compiler, and ParaScope, a parallel programming environment,