Question

[aiwa]

Hi guys , i have a question . Example : i declared 2 int variables .. How do i find which number is minimum and which maximum without using cicles ( for , dowhile , while , if , repeat etc ) ? It is possible ? I asked many people but i didn't find a answer ..

[superbonzo]

do you mean, using only int/binary arithmetics ? take a look at http://graphics.stanford.edu/~seander/bithacks.html

[2kaud]

How do i find which number is minimum and which maximum without using cicles

Why - what are trying to achieve? If using c++ then the STL has min() and max(). For min() see http://www.cplusplus.com/reference/algorithm/min/

[wolle]

How do i find which number is minimum and which maximum without using cicles ( for , dowhile , while , if , repeat etc ) ? It is possible ?

You can use the ternary operator like this,

int max(int a, int b) {
    return (a>b) ? a : b; 
}

It doesn't use any of the control structures you mention but it still involves a conditional selection so it's not branch free (which I suppose your question is about?).

Still there are true branch free alternatives indeed as superbonzo's link shows. Here's another one,

http://bits.stephan-brumme.com/minmax.html

If you not only want to know whether it is possible to have min/max without branching but want to actually use it to optimize real code I think the best option is to use std::min/std::max as 2kaud suggests. I'm sure the C++ standard library implementations of most quality compilers will produce branch free code for these functions in speed optimization mode. In fact I'm so sure I'll eat my hat if they don't.

[superbonzo]

moreover, the min/max standard family of functions also works with references, enabling things like

auto bounds = std::minmax(a,b); 

bounds.first--; // say, decrement the minimum
bounds.second++; // increment the maximum
}

this may lead to cleaner/faster code in some circumstances ...