---
id: pr-cccl-cub-8527
repo: NVIDIA/cccl
pr: 8527
title: '[cudax] Make groups constructible from other groups'
author: davebayer
date: '2026-04-21'
url: https://github.com/NVIDIA/cccl/pull/8527
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: 0caea64d9ef65823b8600f0e72343a2f38ba9361
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- 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/this_group.cuh
- cudax/include/cuda/experimental/__group/traits.cuh
- cudax/test/CMakeLists.txt
- cudax/test/group/cooperative_algorithm.cu
- cudax/test/group/group.cu
- cudax/test/group/make_this_group.cu
- cudax/test/group/mapping/group_by.cu
- cudax/test/group/synchronizer/barrier_synchronizer.cu
- cudax/test/group/synchronizer/lane_synchronizer.cu
- cudax/test/group/this_group.cu
artifact_dir: evidence/pull-bundles/cccl-cub/gh-8527
head_ref_oid: 5a7db81886aac54443f3a54214a496445bff1114
---
# [cudax] Make groups constructible from other groups

- Repository: `NVIDIA/cccl`
- PR: [8527](https://github.com/NVIDIA/cccl/pull/8527)
- 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/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/this_group.cuh`
- `cudax/include/cuda/experimental/__group/traits.cuh`
- `cudax/test/CMakeLists.txt`
- `cudax/test/group/cooperative_algorithm.cu`
- `cudax/test/group/group.cu`
- `cudax/test/group/make_this_group.cu`
- `cudax/test/group/mapping/group_by.cu`
- `cudax/test/group/synchronizer/barrier_synchronizer.cu`
- `cudax/test/group/synchronizer/lane_synchronizer.cu`
- `cudax/test/group/this_group.cu`

## Evidence Bundle

`evidence/pull-bundles/cccl-cub/gh-8527`
