Granted, it's a niche case, though an important one -- using a switch statement for bytecode dispatch leads to poor branch prediction in VMs, and better alternatives require either non-standard extensions (http://eli.thegreenplace.net/2012/07/12/computed-goto-for-ef...) or assembler.
If you're really concerned with performance when writing C, try to avoid painting yourself into a corner. Profile. Consider custom memory allocators, if much of your time is spent creating short-lived or equal-sized objects. In general, look at the tricks the really hardcore game devs do in C++.
Also, use valgrind, because you'll probably cut too many corners. ;)
Granted, it's a niche case, though an important one -- using a switch statement for bytecode dispatch leads to poor branch prediction in VMs, and better alternatives require either non-standard extensions (http://eli.thegreenplace.net/2012/07/12/computed-goto-for-ef...) or assembler.
If you're really concerned with performance when writing C, try to avoid painting yourself into a corner. Profile. Consider custom memory allocators, if much of your time is spent creating short-lived or equal-sized objects. In general, look at the tricks the really hardcore game devs do in C++.
Also, use valgrind, because you'll probably cut too many corners. ;)