---
id: pr-sglang-19794
repo: sgl-project/sglang
pr: 19794
title: Add compile-time 256-bit vector guard for pre-Blackwell
author: xingsy97
date: '2026-03-20'
url: https://github.com/sgl-project/sglang/pull/19794
source_category: upstream-code
architectures:
- sm100
- sm90
tags:
- kernel-fusion
techniques:
- kernel-fusion
hardware_features: []
kernel_types: []
languages:
- cuda-cpp
- python
captured_at: '2026-04-27'
status: merged
merge_sha: f41832795ee73bdc6b1b6e00eff3cd676dc1223f
inclusion_reason: kernel file changes
changed_paths:
- python/sglang/jit_kernel/csrc/elementwise/fused_add_rmsnorm.cuh
- python/sglang/jit_kernel/csrc/elementwise/qknorm_across_heads.cuh
- python/sglang/jit_kernel/include/sgl_kernel/utils.cuh
- python/sglang/jit_kernel/include/sgl_kernel/vec.cuh
head_ref_oid: 7b24cdb3147d72016cd3431a38d1115f2dbab468
artifact_dir: evidence/pull-bundles/sglang/gh-19794
---
# Add compile-time 256-bit vector guard for pre-Blackwell

- Repository: `sgl-project/sglang`
- PR: [19794](https://github.com/sgl-project/sglang/pull/19794)
- Decision: `kernel file changes`
- Reason: kernel file changes

## Changed Paths

- `python/sglang/jit_kernel/csrc/elementwise/fused_add_rmsnorm.cuh`
- `python/sglang/jit_kernel/csrc/elementwise/qknorm_across_heads.cuh`
- `python/sglang/jit_kernel/include/sgl_kernel/utils.cuh`
- `python/sglang/jit_kernel/include/sgl_kernel/vec.cuh`

## Evidence Bundle

`evidence/pull-bundles/sglang/gh-19794`
