C programming tricks

While programming optimization that makes ones' code completely unreadable is often a bad thing, there are places for it, like that one inner loop of your code that takes up 98% of the program's running time.

What are you tricks for improving performance in C, other than the obvious inline assembly or the like?

>>31
FUCK YOU FUCKING FAG
XOR SWAP TWO SIGNED INTEGERS AND TELL ME WHAT HAPPENDS YOU FUCKING PIECE OF SHIT
UNDEFINED BEHAVIOR TOO
I KNOW ALL OF THIS
I LIVE INSIDE STANDARDS