Compilers: Principles and Practice by Pearson

Code Generation and Machine-dependent Optimization 291

c

The L-2 cache’ is normally much bigger, such as 256, 512 or 1024 Kb. The purpose of the

L-2 cache’ is to constantly read in slightly larger quantities of data from the main memory,

so that the information is available to the L-1 cache’. The latency of L-2 cache’ is 6 clock

cycles or 3 nsec. Note that when L-1 is to be reloaded, it is the latency of L-2 which is

applicable.

c

The comments about reloading of the L-1 cache’ from L-2 also apply to loading of L-2 cache’

from the main memory and the same issues of code replacement apply, but now with 3 times

the penalty time.

c

The reloading ...