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?

>>60

1. Use fprintf ("fast printf") instead of printf.

No. Here's an EXPERT PROGRAMMER QUALITY optimization :
fwrite("string",sizeof(char),sizeof("string"),stdout);