Language extensions ?

Fri Mar 28 10:00:00 GMT 2003

Tom Tromey writes:
 > >>>>> "Robin" == Robin Garner <robin.garner@iname.com> writes:
 > 
 > Robin> Sadly, the only way to compare signed integers in an unsigned
 > Robin> way is:
 > Robin> boolean GT(int a, int b) {
 > Robin> if( a > 0 && b > 0 || a < 0 && b < 0 ) 
 > Robin> return a > b;
 > Robin> else
 > Robin> return a < b;
 > Robin> }
 > 
 > Sounds like a puzzle :-)
 > 
 > How about
 > 
 > boolean GT(int a, int b) {
 > return (((long) a) & 0xffffffffL) > (((long) b) & 0xffffffffL);
 > }
It's two's complement arithmetic. Just remove the bias and do the
comparison.
(a ^ 0x80000000) > (b ^ 0x80000000)
Andrew.