This project involves a cache simulator, not a real cache on a computer’s CPU, but a made-up cache that is implemented in software. The cache simulator implements a write-allocate policy for write misses and evicts lines based on LRU.

The cache is assessed according to sequences of memory references from real programs, which are “replayed against” the cache simulator. The sequence of memory references are stored in reference trace files, which are contained in the traces subdirectory. The trace files are generated by a Linux program called valgrind. For example, typing

linux> valgrind --log-fd=1 --tool=lackey -v --trace-mem=yes ls -l

on the command line runs the executable program ls -l, captures a trace of each of its memory accesses in the order they occur, and prints them to stdout.

valgrind memory traces have the following form:

I 0400d7d4,8
 M 0421c7f0,4
 L 04f6b868,8
 S 7ff0005c8,8

Each line denotes one or two memory accesses. The format of each line (except for the instruction loads, which do not include a space character) is

[space]operation address,size

The operation field denotes the type of memory access: I denotes an instruction load, L a data load, S a data store, and M a data modify (i.e., a data load followed by a data store). The address field specifies a 64-bit hexadecimal memory address. The size field specifies the number of bytes accessed by the operation.

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes. Have fun!

1. Clone this repo into your folder of choice.

   $ git clone https://github.com/jackandthebean/csim.git
   

2. Change directories.

   $ cd csim
   

3. Compile the program.

   $ make
   

4. Run the program:

   $ ./csim
   Usage: ./csim [-hv] -s <num> -E <num> -b <num> -t <file>
   Options:
     -h         Print this help message.
     -v         Optional verbose flag.
     -s <num>   Number of set index bits.
     -E <num>   Number of lines per set.
     -b <num>   Number of block offset bits.
     -t <file>  Trace file.
   
   Examples:
     $ ./csim -s 4 -E 1 -b 4 -t traces/yi.trace
     $ ./csim -v -s 8 -E 2 -b 4 -t traces/yi.trace
   

• Atom – open-source text editor
• GCC – C compiler
• Valgrind – memory debugging tool