Question:
I wish to mark a function for more aggressive optimizations. The function is not called often, so PGO won’t help, but I still want it as low latency as possible.gcc has attribute
hot for this. Is there some clang equivalent I’m missing?BTW clang does accept
__attribute__((hot)), but AFAICT it has zero impact (and is undocumented). Probably for source compatibility with gcc.Answer:
(Writing an answer instead of deleting, in case it is of use to others)So turns out that since December 2020 Clang does support
__attribute__((hot)), they just didn’t document it. I nudged them. When tested in a newer clang version I see a difference in binaries.BTW they did support
__attribute__((cold)) long before that. And as I suspected, the clang front end did accept hot for sake of gcc compatibility.If you have better answer, please add a comment about this, thank you!