---
id: pr-sglang-24816
repo: sgl-project/sglang
pr: 24816
title: Add FlashInfer SM90 cutlass MXFP4 MoE backend (W4A16) for GPT-OSS + DeepSeek-V4
author: yuan-luo
date: '2026-05-13'
url: https://github.com/sgl-project/sglang/pull/24816
source_category: upstream-code
architectures:
- sm100
- sm90
tags:
- cutlass
- flashinfer
- fused moe
- gemm_quant
- hopper
- moe kernel
- moe_routing
- mxfp4
- sampling kernel
- sm90
techniques:
- fine-grained-quantization
- kernel-fusion
hardware_features:
- fp4
- fp8
- hopper
- mxfp4
kernel_types:
- gemm
- moe
- sampling
languages:
- cuda-cpp
- cute-dsl
captured_at: '2026-05-16'
status: merged
merge_sha: 28758d37dd5cf6727f487c3867cf7ca9d33fecfe
inclusion_reason: Inspect scale layout, accumulator type, tile/schedule choice, epilogue fusion, and partial-tile guards before deriving a candidate.
changed_paths:
- python/sglang/srt/layers/moe/topk.py
- python/sglang/srt/layers/quantization/fp8.py
- python/sglang/srt/layers/quantization/mxfp4.py
- python/sglang/srt/layers/quantization/mxfp4_flashinfer_cutlass_moe.py
- python/sglang/srt/layers/quantization/mxfp4_flashinfer_trtllm_moe.py
- python/sglang/test/bench_mxfp4_sm90_kernels.py
- test/registered/dsv4/test_deepseek_v4_flash_fp4_h200.py
- test/registered/unit/layers/quantization/test_mxfp4_sm90_cutlass.py
artifact_dir: evidence/pull-bundles/sglang/gh-24816
head_ref_oid: 8ee8ca1f5e472a3f5c15c51a7f22b52229190f68
---
# Add FlashInfer SM90 cutlass MXFP4 MoE backend (W4A16) for GPT-OSS + DeepSeek-V4

- Repository: `sgl-project/sglang`
- PR: [24816](https://github.com/sgl-project/sglang/pull/24816)
- Decision: `Inspect scale layout, accumulator type, tile/schedule choice, epilogue fusion, and partial-tile guards before deriving a candidate.`
- Reason: Inspect scale layout, accumulator type, tile/schedule choice, epilogue fusion, and partial-tile guards before deriving a candidate.

## Changed Paths

- `python/sglang/srt/layers/moe/topk.py`
- `python/sglang/srt/layers/quantization/fp8.py`
- `python/sglang/srt/layers/quantization/mxfp4.py`
- `python/sglang/srt/layers/quantization/mxfp4_flashinfer_cutlass_moe.py`
- `python/sglang/srt/layers/quantization/mxfp4_flashinfer_trtllm_moe.py`
- `python/sglang/test/bench_mxfp4_sm90_kernels.py`
- `test/registered/dsv4/test_deepseek_v4_flash_fp4_h200.py`
- `test/registered/unit/layers/quantization/test_mxfp4_sm90_cutlass.py`

## Evidence Bundle

`evidence/pull-bundles/sglang/gh-24816`
