For the Intel architectures, is there a way to instruct the GCC compiler to generate code that always forces branch prediction a particular way in my code? Does the Intel hardware even support this? What about other compilers or hardwares?
I would use this in C++ code where I know the case I wish to run fast and do not care about the slow down when the other branch needs to be taken even when it has recently taken that branch.
for (;;) {
if (normal) { // How to tell compiler to always branch predict true value?
doSomethingNormal();
} else {
exceptionalCase();
}
}
As a follow on question for Evdzhan Mustafa, can the hint just specify a hint for the first time the processor encounters the instruction, all subsequent branch prediction, functioning normally?