---
id: pr-cccl-cub-7334
repo: NVIDIA/cccl
pr: 7334
title: Implement the new tuning API for `DeviceSegmentedReduce`
author: bernhardmgruber
date: '2026-01-29'
url: https://github.com/NVIDIA/cccl/pull/7334
source_category: upstream-code
architectures:
- sm100
tags:
- sm100
techniques: []
hardware_features:
- blackwell
kernel_types: []
languages: []
captured_at: '2026-05-16'
status: merged
merge_sha: ce3629efcbe10160af85a7d537578a60884f978a
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- c/parallel/src/reduce.cu
- c/parallel/src/segmented_reduce.cu
- cub/cub/agent/agent_reduce.cuh
- cub/cub/device/device_segmented_reduce.cuh
- cub/cub/device/dispatch/dispatch_common.cuh
- cub/cub/device/dispatch/dispatch_fixed_size_segmented_reduce.cuh
- cub/cub/device/dispatch/dispatch_reduce.cuh
- cub/cub/device/dispatch/dispatch_segmented_reduce.cuh
- cub/cub/device/dispatch/kernels/kernel_segmented_reduce.cuh
- cub/cub/device/dispatch/tuning/common.cuh
- cub/cub/device/dispatch/tuning/tuning_reduce.cuh
- cub/cub/device/dispatch/tuning/tuning_segmented_reduce.cuh
- cub/test/catch2_test_device_reduce_env.cu
artifact_dir: evidence/pull-bundles/cccl-cub/gh-7334
head_ref_oid: 386df0e32b54fda2df68351f87061404d1b7a61b
---
# Implement the new tuning API for `DeviceSegmentedReduce`

- Repository: `NVIDIA/cccl`
- PR: [7334](https://github.com/NVIDIA/cccl/pull/7334)
- 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

- `c/parallel/src/reduce.cu`
- `c/parallel/src/segmented_reduce.cu`
- `cub/cub/agent/agent_reduce.cuh`
- `cub/cub/device/device_segmented_reduce.cuh`
- `cub/cub/device/dispatch/dispatch_common.cuh`
- `cub/cub/device/dispatch/dispatch_fixed_size_segmented_reduce.cuh`
- `cub/cub/device/dispatch/dispatch_reduce.cuh`
- `cub/cub/device/dispatch/dispatch_segmented_reduce.cuh`
- `cub/cub/device/dispatch/kernels/kernel_segmented_reduce.cuh`
- `cub/cub/device/dispatch/tuning/common.cuh`
- `cub/cub/device/dispatch/tuning/tuning_reduce.cuh`
- `cub/cub/device/dispatch/tuning/tuning_segmented_reduce.cuh`
- `cub/test/catch2_test_device_reduce_env.cu`

## Evidence Bundle

`evidence/pull-bundles/cccl-cub/gh-7334`
