$ LD_PRELOAD=/usr/local/lib/libmimalloc.so NUM_THREADS=6 ./llil4vec-new big1.txt big2.txt big3.txt >f.tmp
llil4vec (fixed string length=6) start
use OpenMP
use boost sort
nthrs=6
get properties         0.192 secs
sort properties        0.261 secs
vector reduce          0.033 secs
vector stable sort     0.186 secs
write stdout           0.311 secs
total time             0.986 secs
$ LD_PRELOAD=/usr/local/lib/libmimalloc.so NUM_THREADS=6 ./llil4vec-new big1.txt big2.txt big3.txt >f.tmp
llil4vec (fixed string length=6) start
use OpenMP
use boost sort
nthrs=6
get properties         0.201 secs
sort properties        0.257 secs
vector reduce          0.032 secs
vector stable sort     0.194 secs
write stdout           0.300 secs
total time             0.986 secs
$ cmp f.tmp big-3vec.tmp