Inferring Cache Geometries

Chip D. Signer, Ph.D, is trying to reverse engineer a competitor's microprocessors to discover their cache geometry. Instead of running programs on these processors and inferring the cache layout from timing results, we will approximate his work by using a simulator.

Specifically, each of these "processors" is provided as an object file (.o file) against which you will link your code. See the file mystery-cache.h for documentation of the function interface that these object files export. Your job is to fill in the function stubs in cache-test-skel.c which, when linked with one of these cache object files, will determine and then output the cache size, associativity, and block size. Some of the provided object files are named with this information (e.g. cache_64c_2a_16b.o is a 64 KB capacity, 2-way set-associative cache with 16B blocks) to help you check your work. There are also 3 mystery cache object files, whose parameters you must discover on your own.

You can assume that the mystery caches have sizes that are powers of 2. You cannot assume anything else about the cache parameters except what you can infer from the cache size. Finally, the mystery caches are all pretty realistic in their geometries, so use this fact to sanity check your results.

You will need to complete this assignment on a Linux machine. All the files you need are in hw3.tar.gz. To extract the files from this archive, simply use the command:

tar xzf hw3.tar.gz

and the files will be extracted into the current directory. The provided Makefile includes a target cache-test. To use it, set TEST_CACHE to the object file to link against on the command line - i.e. run the command:

make cache-test TEST_CACHE=cache_64c_2a_16b.o

This will create an executable cache-test that will run your cache-inference code against the supplied cache object. Run this executable like so:

./cache-test

and it will print the results to the screen.

Inferring Cache Geometries

What you need to do

Turning in the assignment


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