---
id: pr-cccl-cub-8299
repo: NVIDIA/cccl
pr: 8299
title: Extract first histogram-only pass in `DeviceTopK` into its own kernel
author: elstehle
date: '2026-04-13'
url: https://github.com/NVIDIA/cccl/pull/8299
source_category: upstream-code
architectures:
- sm100
tags:
- benchmark kernel
techniques: []
hardware_features: []
kernel_types: []
languages:
- cuda-cpp
captured_at: '2026-05-16'
status: merged
merge_sha: f984c90df50195e3d73b8f5aa1e1e28ae030c4bd
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- cub/cub/agent/agent_topk.cuh
- cub/cub/device/dispatch/dispatch_topk.cuh
artifact_dir: evidence/pull-bundles/cccl-cub/gh-8299
head_ref_oid: 0c0281cce4e7a9bb14ecd32f82727cd04d5498ab
---
# Extract first histogram-only pass in `DeviceTopK` into its own kernel

- Repository: `NVIDIA/cccl`
- PR: [8299](https://github.com/NVIDIA/cccl/pull/8299)
- 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/agent/agent_topk.cuh`
- `cub/cub/device/dispatch/dispatch_topk.cuh`

## Evidence Bundle

`evidence/pull-bundles/cccl-cub/gh-8299`
