---
id: pr-cccl-cub-8523
repo: NVIDIA/cccl
pr: 8523
title: '[cudax] Implement public groups synchronizers'
author: davebayer
date: '2026-04-21'
url: https://github.com/NVIDIA/cccl/pull/8523
source_category: upstream-code
architectures:
- sm100
tags:
- warp
techniques:
- warp-specialization
hardware_features: []
kernel_types: []
languages:
- cuda-cpp
captured_at: '2026-05-16'
status: merged
merge_sha: 8a63a407cc46858c4d42e2069d7e92fc1b61ef43
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- cudax/include/cuda/experimental/__group/concepts.cuh
- cudax/include/cuda/experimental/__group/fwd.cuh
- cudax/include/cuda/experimental/__group/group.cuh
- cudax/include/cuda/experimental/__group/mapping/group_by.cuh
- cudax/include/cuda/experimental/__group/synchronizer/barrier_synchronizer.cuh
- cudax/include/cuda/experimental/__group/synchronizer/lane_synchronizer.cuh
- cudax/include/cuda/experimental/__group/traits.cuh
- cudax/include/cuda/experimental/group.cuh
- cudax/test/CMakeLists.txt
- cudax/test/group/group.cu
- cudax/test/group/mapping/group_by.cu
- cudax/test/group/synchronizer/barrier_synchronizer.cu
- cudax/test/group/synchronizer/lane_synchronizer.cu
artifact_dir: evidence/pull-bundles/cccl-cub/gh-8523
head_ref_oid: bef55e3c3c7fdad3d91e8610e460b2defd0d0655
---
# [cudax] Implement public groups synchronizers

- Repository: `NVIDIA/cccl`
- PR: [8523](https://github.com/NVIDIA/cccl/pull/8523)
- Decision: `Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.`
- Reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.

## Changed Paths

- `cudax/include/cuda/experimental/__group/concepts.cuh`
- `cudax/include/cuda/experimental/__group/fwd.cuh`
- `cudax/include/cuda/experimental/__group/group.cuh`
- `cudax/include/cuda/experimental/__group/mapping/group_by.cuh`
- `cudax/include/cuda/experimental/__group/synchronizer/barrier_synchronizer.cuh`
- `cudax/include/cuda/experimental/__group/synchronizer/lane_synchronizer.cuh`
- `cudax/include/cuda/experimental/__group/traits.cuh`
- `cudax/include/cuda/experimental/group.cuh`
- `cudax/test/CMakeLists.txt`
- `cudax/test/group/group.cu`
- `cudax/test/group/mapping/group_by.cu`
- `cudax/test/group/synchronizer/barrier_synchronizer.cu`
- `cudax/test/group/synchronizer/lane_synchronizer.cu`

## Evidence Bundle

`evidence/pull-bundles/cccl-cub/gh-8523`
