ws-64:/home/qi/wernermisc/bitcmp# ./bitcmp -w -B ~/m1/0x39.bit ~/m1/0x3a-1.bit 
 7: 625
14: 337

ws-64:/home/qi/wernermisc/bitcmp# ./bitcmp -w -B ~/m1/0x39.bit ~/m1/0x3a-2.bit 

ws-64:/home/qi/wernermisc/bitcmp# ./bitcmp -w -B ~/m1/0x39.bit ~/m1/0x3a-4.bit 
15: 19512