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Analysis Phase

Interestingly enough, the locality analysis that we used to predict the caching behavior of affine references (see Section ) cannot work for indirect references, since there is no way to predict at compile-time which data are being accessed. At one extreme, all of the index values may be identical, and the reference would behave as though it had temporal locality. At the other extreme, each reference may point to a unique cache line, and the reference would behave as though it had no locality. Since we are unable to accurately predict data locality for this case, the two choices are to prefetch all the time or not at all (i.e. there is no such thing as ``loop splitting'' for this case). For these experiments, we decided to prefetch indirect references all the time. To improve this decision-making process further, profiling feedback or hardware miss counters may prove useful, as we will discuss later in Section .

Sat Jun 25 15:13:04 PDT 1994