Skip to content

GPUCommonAlgorithm: partitionPoint #15985

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
davidrohr merged 1 commit into from
Oct 20, 2026
+20 −0
Merged

GPUCommonAlgorithm: partitionPoint #15985

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 20 additions & 0 deletions GPU/Common/GPUCommonAlgorithm.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -49,6 +49,8 @@ class GPUCommonAlgorithm
#endif
template <class T>
GPUd() static void swap(T& a, T& b);
template <class I, class P>
GPUhd() static I partitionPoint(I first, I count, const P& pred);

private:
template <typename I>
Expand Down Expand Up @@ -330,6 +332,24 @@ GPUdi() void GPUCommonAlgorithm::swap(T& a, T& b)
}
#endif

// std::partition_point over the indices [first, first + count): the first index for which pred is false, pred being true on a prefix.
// A lower bound of value in a sorted key(i) is pred(i) = key(i) < value, an upper bound pred(i) = !(value < key(i)).
template <class I, class P>
GPUhdi() I GPUCommonAlgorithm::partitionPoint(I first, I count, const P& pred)
{
while (count > 0) {
const I step = count / 2;
const I middle = first + step;
if (pred(middle)) {
first = middle + 1;
count -= step + 1;
} else {
count = step;
}
}
return first;
}

} // namespace o2::gpu

// ----------------------------- WORK GROUP FUNCTIONS -----------------------------
Expand Down
Loading