a Predicated ADD would need to also read the predicate register file. This increases Hazards in Out-of-order execution.
*Predication is not usually speculated and causes a longer dependency chain. For ordered data this translates to a performance loss compared to a predictable branch.

Predication is most effective when paths are balanced or when the longest path is the most frequently executed, but determining such a path is very difficult at compile time, even in the presence of profiling information.