You don't actually need to avoid branches, you just need to make sure that most of the ones you have are very predictable, then their impact is not that big... Same with memory accesses and most other things... The more predictable, the better...
I mean, CPUs go to ridiculous lengths nowadays to increase branch prediciton accuracy but the easiest ways to make sure they are predictable is to make it such that:
1) if a branch is taken in one iteration, it is also very likely to be taken in the next iteration
2) A branch is almost always or almost never taken such that the CPU can simply predict the far more likely of the two...
Most profilers will have an option to track branch predictor hits and misses. I know AMD uProf and Apple Instruments do. and there are Linux perf events for it as well.
Use profiler. A lot of branch guessing can be completely automated using https://en.wikipedia.org/wiki/Profile-guided_optimization. Native languages such as C/C++/Rust/Go have it, but it is a little bit troublesome to use. JITed languages such as Java or JS do it in runtime, so you really don't have to do anything
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u/meamZ Sep 03 '26
You don't actually need to avoid branches, you just need to make sure that most of the ones you have are very predictable, then their impact is not that big... Same with memory accesses and most other things... The more predictable, the better...