added some common arithmetic functions
added some common arithmetic functions

Change-Id: I6fb164670571b79050fdfccc919ee256e194a396

8l/connectal,hanw/connectal,csail-csg/connectal,csail-csg/connectal,chenm001/connectal,cambridgehackers/connectal,cambridgehackers/connectal,hanw/connectal,csail-csg/connectal,8l/connectal,hanw/connectal,8l/connectal,cambridgehackers/connectal,hanw/connectal,csail-csg/connectal,chenm001/connectal,chenm001/connectal,cambridgehackers/connectal,cambridgehackers/connectal,8l/connectal,8l/connectal,hanw/connectal,chenm001/connectal,chenm001/connectal,csail-csg/connectal