$ NUM_THREADS=6 ./llil4vec2 big1.txt big2.txt big3.txt >f.tmp
llil4vec2 (fixed string length=6) use memcmp start
use OpenMP
use boost sort
get properties      time :    0.311 secs
sort properties     time :    0.261 secs
vector reduce       time :    0.030 secs
vector stable sort  time :    0.199 secs
write stdout        time :    0.316 secs
total               time :    1.120 secs