问题
I know that I can get the total percentage of branch mispredictions during the execution of a program with perf stat. But how can I get the statistics for a specific branch (if or switch statement in C code)?
回答1:
You can sample on the branch-misses event:
sudo perf record -e branch-misses <yourapp>
and then report it (and even selecting the function you're interested in):
sudo perf report -n --symbols=<yourfunction>
There you can access the annotated code and get some statistics for a given branch. Or directly annotate it with the perf command with --symbol option.
来源：https://stackoverflow.com/questions/33523301/how-to-measure-mispredictions-for-a-single-branch-on-linux