The extended mapping features permit greater control over the mapping of data, including facilities for dynamic realignment and redistribution of arrays at run-time (REALIGN, REDISTRIBUTE, DYNAMIC directives), mapping of data among subsets of processors, mapping of pointers and components of derived types, and support for irregular distribution of data (GEN_BLOCK and INDIRECT distributions). In addition, mechanisms are defined that permit the programmer to provide information to the compiler about the range of possible distributions an array might take (RANGE directive) and the amount of buffering to be used with arrays involved in stencil-based nearest-neighbor computations (SHADOW).