This suggests prefetch
policies that progressively fetch larger numbers of pages as the run size increases.
To provide better support for instruction prefetching, we further enhanced the primary instruction cache relative to the R10000 as follows: we divide it into four separate banks, and we add an eight-entry victim cache [Jouppi 1990] and a 16-entry prefetch
buffer [Joseph and Grunwald 1997].
Consider one of the D - 1 prefetch
operations that do not have an eviction assigned.
that causes a miss in the cache that would not have occurred if prefetching was not in use is defined as cache pollution.
Alternatively, users may also specify the amount of XMS memory assigned to the data cache and system memory assigned to the prefetch
We have also evaluated the prefetch
schemes using a metric called the percentage of unused prefetch
Saavedra and Park describe the application of such an adaptive execution technique to determine, at run time, the best value for the prefetch
distance in an algorithm that prefetches
data accessed by a loop [Saavedra and Park 1996].
User specification of caching and prefetch
In addition, the SH7216 group implements advanced prefetch
and cache techniques to deliver up to 400DMIPS of performance while executing from flash, and 480DMIPS while executing from RAM.
More specifically, SSE2 has the memory streaming instruction extensions, which allows programmers to prefetch
data into a specified level of the cache hierarchy.
A scheduling optimization technique may prefetch
or presend some data objects to overlap computation and communication, but it may require extra temporary space to hold these data objects.
In processors that implement hardware prefetching or speculative execution, it may be difficult or impossible to separate "true" memory references from those that occur due to a prefetch
that might not actually be used.