follow up question: if the branch is predicted to not be taken, why does the predictor have to use resources to record its location and the destination?
These predictors change their prediction (both direction and destination) based on the history of the last few hundred branches and if they were taken or not-taken. So the predictor needs to know where those branches were, even if they aren't taken.
Indirect TAGE predictors are very powerful. They can correctly predict jump tables and virtual function calls.
In general, branch predictors don't utilise their tables very efficiently. Cheap and fast lookups are way more important than minimising size.
follow up question: if the branch is predicted to not be taken, why does the predictor have to use resources to record its location and the destination?