---
id: pr-cccl-cub-6329
repo: NVIDIA/cccl
pr: 6329
title: Improve `cuda::barrier` TMA examples and `elect_one` in `DeviceTransform`
author: bernhardmgruber
date: '2025-10-27'
url: https://github.com/NVIDIA/cccl/pull/6329
source_category: upstream-code
architectures:
- sm90
tags:
- sm90
techniques:
- async-copy
hardware_features:
- hopper
- tma
kernel_types: []
languages:
- cuda-cpp
captured_at: '2026-05-16'
status: merged
merge_sha: c2d957e4198cc5e449649e8ea5fea39f232aaa92
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- cub/cub/device/dispatch/kernels/transform.cuh
- docs/libcudacxx/extended_api/asynchronous_operations/memcpy_async_tx.rst
- docs/libcudacxx/extended_api/synchronization_primitives/barrier.rst
- libcudacxx/include/cuda/__memcpy_async/elect_one.h
artifact_dir: evidence/pull-bundles/cccl-cub/gh-6329
head_ref_oid: f97b4e3db5841f84b4024cd31f35b53837117000
---
# Improve `cuda::barrier` TMA examples and `elect_one` in `DeviceTransform`

- Repository: `NVIDIA/cccl`
- PR: [6329](https://github.com/NVIDIA/cccl/pull/6329)
- 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

- `cub/cub/device/dispatch/kernels/transform.cuh`
- `docs/libcudacxx/extended_api/asynchronous_operations/memcpy_async_tx.rst`
- `docs/libcudacxx/extended_api/synchronization_primitives/barrier.rst`
- `libcudacxx/include/cuda/__memcpy_async/elect_one.h`

## Evidence Bundle

`evidence/pull-bundles/cccl-cub/gh-6329`
