computes a hashcode for an integer inspired by thomas wang 's function , described at http://www.concentric.net/~ttwang/tech/inthash.htm concode_field_sep PlaceHolder placeHolder concode_field_sep placeholderType placeHolder
int function ( int arg0 ) { arg0 = ~ arg0 + ( arg0 << 15 ) ; arg0 ^= arg0 >>> 12 ; arg0 += arg0 << 2 ; arg0 ^= arg0 >>> 4 ; arg0 *= 2057 ; arg0 ^= arg0 >>> 16 ; return arg0 ; }