question: public static long [ ] truncateI ( long [ ] v , int len ) { final int zap = ( v . length * Long . SIZE ) - len ; final int zapWords = ( zap > > > LONG_LOG2_SIZE ) ; final int zapbits = zap & LONG_LOG2_MASK ; Arrays . fill ( v , v . length - zapWords , v . length , 0 ) ; if ( zapbits > 0 ) { v [ v . length - zapWords - 1 ] &= ( LONG_ALL_BITS > > > zapbits ) ; } return v ; }
target:  Truncate a bit string to the given length (setting any higher bit to 0).