An excerpt from the abstract:
Loop vectorization has been found to be one of the most significant forms of parallelism. However, it has traditionally been limited to innermost loops and outer loops which are made innermost by the application of loop distribution and interchange. We propose a framework for direct vectorization of outer loops (OLV): i.e., vectorization of an outer loop without interchange or distribution. The framework includes: general vector execution modeling, legality of OLV, vector loop selection, and an OLV vector code generator.These techniques have been implemented in the Cray Fortran-90 compiling system. Implementation details are presented. The efficacy of these techniqeus are demonstrated by significant performance improvement of application programs.