---
id: pr-cccl-cub-6597
repo: NVIDIA/cccl
pr: 6597
title: Split fixed-size segmented reduce dispatch header
author: bernhardmgruber
date: '2025-11-14'
url: https://github.com/NVIDIA/cccl/pull/6597
source_category: upstream-code
architectures:
- sm100
tags:
- memory_primitives
- scheduler_autotune
- segmented reduce
techniques:
- autotuning
- tile-scheduling
hardware_features: []
kernel_types:
- memory
- scheduler
languages:
- cuda-cpp
captured_at: '2026-05-16'
status: merged
merge_sha: 60d6345f161728b175f57550657511667ea4fb54
inclusion_reason: 'Transfer primitive policy carefully: coalescing, shared-memory staging, partial tiles, and determinism are part of the contract.'
changed_paths:
- c/parallel/src/segmented_reduce.cu
- cub/cub/device/device_segmented_reduce.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
artifact_dir: evidence/pull-bundles/cccl-cub/gh-6597
head_ref_oid: 01b426f35e7c0afa781cae9985be8c71d96e7baf
---
# Split fixed-size segmented reduce dispatch header

- Repository: `NVIDIA/cccl`
- PR: [6597](https://github.com/NVIDIA/cccl/pull/6597)
- Decision: `Transfer primitive policy carefully: coalescing, shared-memory staging, partial tiles, and determinism are part of the contract.`
- Reason: Transfer primitive policy carefully: coalescing, shared-memory staging, partial tiles, and determinism are part of the contract.

## Changed Paths

- `c/parallel/src/segmented_reduce.cu`
- `cub/cub/device/device_segmented_reduce.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`

## Evidence Bundle

`evidence/pull-bundles/cccl-cub/gh-6597`
