---
id: pr-cccl-cub-8328
repo: NVIDIA/cccl
pr: 8328
title: Disable `__block_dims__` kernel launcher
author: davebayer
date: '2026-04-08'
url: https://github.com/NVIDIA/cccl/pull/8328
source_category: upstream-code
architectures:
- sm100
tags:
- block
techniques: []
hardware_features: []
kernel_types: []
languages:
- cuda-cpp
captured_at: '2026-05-16'
status: merged
merge_sha: 3a82c109e551050afb0797d1650ca3c60b069a1e
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- cudax/test/hierarchy/group.cu
- libcudacxx/include/cuda/__launch/launch.h
- libcudacxx/test/libcudacxx/cuda/ccclrt/launch/launch_smoke.cu
artifact_dir: evidence/pull-bundles/cccl-cub/gh-8328
head_ref_oid: 14e8559372373b4a478a00be636d6810cb639356
---
# Disable `__block_dims__` kernel launcher

- Repository: `NVIDIA/cccl`
- PR: [8328](https://github.com/NVIDIA/cccl/pull/8328)
- 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

- `cudax/test/hierarchy/group.cu`
- `libcudacxx/include/cuda/__launch/launch.h`
- `libcudacxx/test/libcudacxx/cuda/ccclrt/launch/launch_smoke.cu`

## Evidence Bundle

`evidence/pull-bundles/cccl-cub/gh-8328`
