---
id: pr-cccl-cub-6926
repo: NVIDIA/cccl
pr: 6926
title: Expose not guaranteed determinism to reduce in cuda.compute
author: NaderAlAwar
date: '2025-12-11'
url: https://github.com/NVIDIA/cccl/pull/6926
source_category: upstream-code
architectures:
- sm100
tags:
- sm100
techniques: []
hardware_features:
- blackwell
kernel_types: []
languages:
- cuda-cpp
captured_at: '2026-05-16'
status: merged
merge_sha: 77f7c106ac4a8dd2c20ac83d82ef9fd1279b191f
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- c/parallel/include/cccl/c/reduce.h
- c/parallel/include/cccl/c/types.h
- c/parallel/src/nvrtc/command_list.h
- c/parallel/src/reduce.cu
- c/parallel/test/test_reduce.cpp
- c/parallel/test/test_segmented_reduce.cpp
- python/cuda_cccl/cuda/compute/__init__.py
- python/cuda_cccl/cuda/compute/_bindings.pyi
- python/cuda_cccl/cuda/compute/_bindings_impl.pyx
- python/cuda_cccl/cuda/compute/algorithms/_reduce.py
- python/cuda_cccl/cuda/compute/determinism.py
- python/cuda_cccl/tests/compute/test_reduce.py
artifact_dir: evidence/pull-bundles/cccl-cub/gh-6926
head_ref_oid: b3337749b21d9ba09eefa811166d63c0a92028cd
---
# Expose not guaranteed determinism to reduce in cuda.compute

- Repository: `NVIDIA/cccl`
- PR: [6926](https://github.com/NVIDIA/cccl/pull/6926)
- 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/include/cccl/c/reduce.h`
- `c/parallel/include/cccl/c/types.h`
- `c/parallel/src/nvrtc/command_list.h`
- `c/parallel/src/reduce.cu`
- `c/parallel/test/test_reduce.cpp`
- `c/parallel/test/test_segmented_reduce.cpp`
- `python/cuda_cccl/cuda/compute/__init__.py`
- `python/cuda_cccl/cuda/compute/_bindings.pyi`
- `python/cuda_cccl/cuda/compute/_bindings_impl.pyx`
- `python/cuda_cccl/cuda/compute/algorithms/_reduce.py`
- `python/cuda_cccl/cuda/compute/determinism.py`
- `python/cuda_cccl/tests/compute/test_reduce.py`

## Evidence Bundle

`evidence/pull-bundles/cccl-cub/gh-6926`
