---
id: pr-cccl-cub-8169
repo: NVIDIA/cccl
pr: 8169
title: Fix UB in `cuda::device::warp_match_all`
author: davebayer
date: '2026-03-25'
url: https://github.com/NVIDIA/cccl/pull/8169
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: 50a11893c2a681bb68dd567858a6181d9f146499
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- libcudacxx/include/cuda/__warp/warp_match_all.h
artifact_dir: evidence/pull-bundles/cccl-cub/gh-8169
head_ref_oid: ed4d22c12f352a3cd3d0ba3483f8daac6bc011c2
---
# Fix UB in `cuda::device::warp_match_all`

- Repository: `NVIDIA/cccl`
- PR: [8169](https://github.com/NVIDIA/cccl/pull/8169)
- 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

- `libcudacxx/include/cuda/__warp/warp_match_all.h`

## Evidence Bundle

`evidence/pull-bundles/cccl-cub/gh-8169`
