Forums Bug Reports $isbit seems buggy

$isbit seems buggy when handling large numbers (64bits)

//echo -a $base(9223372208653468868,10,2)
//echo -a $isbit(9223372208653468868,1)

Should returns 0, but returns 1

using mIRC 6.14

mIRC makes no warranty for the calculation of numbers greater than 15 digits in length.

This is a conservative figure, as some functions work just fine for values 16 digits and longer. However, most of mIRC's math uses a 64 bit floating point, which leaves only 48 bits for intergers.

Just avoid figures greater than 281474976710655. ( 2^48 - 1 )

___

PS. Again, 2^48 is a conservative safety limit.
$calc appears to get 2^49 through 2^56 correct, yet it can't even add:
9999999999999998 + 1 (which only uses 54 bits of memory, and is 16 digits long)
While 2^56 == 72057594037927936 (which needs 57 bits of memory, and is 17 digits)

beats me.

After wasting more time on this, cuz I obviously have nothing better to do, I've come to the conclusion that the largest number mIRC can accurately calculate in successive series is:

2^53 or 9007199254740992

Any odd number results larger than this are rounded down to the nearest even number, giving a false sense of accuracy, as some of your answers are correct some of the time.

In short, mIRC does not support numbers larger than 2^53 with any warranty of accuracy.

- Raccoon

okay! Thanks for the information!