VECTORS TO VICTORY!!!

The programs in this repository solve the ClusterFights Gutenberg/MD5 challenge, This program uses vectors to compute the MD5 sums. It is intended to run on an Intel processor with AVX2.

The program 'shm_init' copies the Gutenberg text from files in the /mnt/md5/guten directory into a shared memory segment located in /dev/shm/gutenberg. The data set is only 400MB and fits easily in system RAM. As the data is copied CRLF is converted to a null, and lines shorter than the target length are removed entirely.

Build and run shm_init as:

gcc -o shm_init shm_init.c  -lrt

./shm_init <substring length>

The program 'shm_vec_md5' searches /dev/shm/gutenberg for the substring matching the specified MD5 sum. You have to compile shm_vec_md5 to match the length of the substring. The #define to change is called 'Sublen'.

Edit shm_vec_md5.c to set Sublen and then build and run as:

gcc -o shm_vec_md5 shm_vec_md5.c -lpthread -lrt -march=broadwell -mavx2 -O3

./shm_vec_md5 <number of thread> <MD5 sum to find>