How efficient is an if statement compared to a test that doesn't use an if? (C++)
- by Keand64
I need a program to get the smaller of two numbers, and I'm wondering if using a standard "if x is less than y"
int a, b, low;
if (a < b) low = a;
else low = a;
is more or less efficient than this:
int a, b, low;
low = b + ((a - b) & ((a - b) >> 31));
(or the variation of putting int delta = a - b at the top and rerplacing instances of a - b with that).
I'm just wondering which one of these would be more efficient (or if the difference is to miniscule to be relevant), and the efficiency of if-else statements versus alternatives in general.
