Growing discord: programming philosophy and hardware design

Generally, vector compiler technology has been successful in achieving reasonable peak efficiency on "good" code. Moreover, the community's ability to generate "good" vector code has improved dramatically. As we move into the era of parallelism, particularly in supercomputing, we can observe certain trends among the leaders in compiler technology. The basic techniques are extensions of strategies for vector machines, but have limited effectiveness in a parallel environment. In this paper, current techniques are examined with respect to choices or trends in hardware design. The ability for parallel compilers to be as effective on parallel machines, as they have been on vector machines is not likely. Technical reasons for this are presented. The human intervention to achieve peak optimization seems to be inevitable. The nature of automatic and non-automatic code optimization is explored.