---
id: pr-cccl-cub-8540
repo: NVIDIA/cccl
pr: 8540
title: Properly migrate scan_by_key benchmark to policy_selector.
author: griwes
date: '2026-04-21'
url: https://github.com/NVIDIA/cccl/pull/8540
source_category: upstream-code
architectures:
- sm100
tags:
- scan
techniques: []
hardware_features: []
kernel_types:
- scan
languages: []
captured_at: '2026-05-16'
status: merged
merge_sha: 59fb9c0d335603ab0dca46224e6058411b3d41c2
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- cub/benchmarks/bench/scan/exclusive/by_key.cu
- cub/cub/device/dispatch/tuning/tuning_scan_by_key.cuh
artifact_dir: evidence/pull-bundles/cccl-cub/gh-8540
head_ref_oid: 833e0f053ae112484032f8815bd7d0ca64a0d927
---
# Properly migrate scan_by_key benchmark to policy_selector.

- Repository: `NVIDIA/cccl`
- PR: [8540](https://github.com/NVIDIA/cccl/pull/8540)
- 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/benchmarks/bench/scan/exclusive/by_key.cu`
- `cub/cub/device/dispatch/tuning/tuning_scan_by_key.cuh`

## Evidence Bundle

`evidence/pull-bundles/cccl-cub/gh-8540`
