Faster way for boolean XOR?

Bobb Fwed

Is there a better way (there almost always is) to do a conditional XOR?

IF ((cond1 AND NOT(cond2)) OR (NOT(cond1) AND cond2))

Phil Pilgrim (PhiPi)

You could do this:

if ((cond1 <> 0) ^ (cond2 <> 0))

This applies a bitwise XOR to the true (-1) or false (0) values of the two <> 0 comparisons. ('Dunno why Spin lacks a logical XOR.)

-Phil

lonesock

maybe "if not(a) <> not(b)" ?
Jonathan

Phil Pilgrim (PhiPi)

I like Jonathan's idea better.

-Phil

Mike Green

How about "if a <> b" where a and b are Boolean values (0 or -1)? This is true only if (a is true and b is false) or (a is false and b is true).

Bobb Fwed

I'm I'm doing bit tests for the conditions. I would imagine (though I haven't tested it) that it is faster to just use NOT() on both the tests, than it is to == the values; so going back to Jonathan's solution.

I tested it, it is fastest.