I have this code which runs a lot of times:

Code:
int z = 10;
int x = b * z;
I know my program assing b = 0 about 35% of times. Does the CPU or compiled code runs into a complete multiplication routines, or does it returns 0 fast?

I ask this because I dont know if for speed optimization is better to put this code:

Code:
int z = 10;
if (b) x = b*z;
what is faster?

thanks
FS