Figure e-6 – Intel ARCHITECTURE IA-32 User Manual

Page 558

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IA-32 Intel® Architecture Optimization

E-12

Now for the case T

l

=18, T

b

=8 (2 cache lines are needed per iteration)

examine the following graph. Consider the graph of accesses per
iteration in example 1, Figure E-6.

The prefetch scheduling distance is a step function of T

c

, the

computation latency. The steady state iteration latency (il) is either
memory-bound or compute-bound depending on T

c

if prefetches are

scheduled effectively.

The graph in example 2 of accesses per iteration in Figure E-7 shows
the results for prefetching multiple cache lines per iteration. The cases
shown are for 2, 4, and 6 cache lines per iteration, resulting in differing
burst latencies. (T

l

= 18, T

b

= 8, 16, 24).

Figure E-6 Accesses per Iteration, Example 1

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