This PR adds the SMS prefetcher described in [this ](https://web.eecs.umich.edu/~twenisch/papers/isca06.pdf) paper. This work was done in collaboration with @Setu-Gupta, and @xmlizhao On branch sms Changes to be committed: modified: src/mem/cache/prefetch/Prefetcher.py modified: src/mem/cache/prefetch/SConscript new file: src/mem/cache/prefetch/sms.cc new file: src/mem/cache/prefetch/sms.hh Change-Id: I68d3bb6cf07385177d0f776fb958f652cfc41489