Optimize all_of / any_of / none_of for vector<bool> with some predicates
#5802
+268
−15
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Towards #625, specifically #625 (comment) items 5, 6, 7
Follow up to #5769
⚙️ Optimization
Similarly to
transform, we can map bool functor to underlying integer vector functor. Although we have to do the operation on integer of bits after this.identitylooking like ideal functor to use, asbools are already boolean, and we just need to apply the algorithm. We can also supportlogical_not, which we have already mapped, although it is obscure to use.Sure
identityis C++20, but that's fine to optimize only new standard modes.As the algorithm uses one range, we can handle any offset without introducing too much complexity. Some complexity is still introduced by this though.
As the resulting flow is not very simple, but is the same for all three, the traits approach from the vector algorithms seems suitable.
Vectorization
Auto vectorization does not work here. @Alcaro suggested that from abstract machine view point the memory load would be invented if they happen past the early return point.
We can vectorize manually. It will be inefficient if early return happens really early, but may be a good idea overall. Not this time though.
⏱️ Benchmark results