---
id: pr-vllm-41882
repo: vllm-project/vllm
pr: 41882
title: Add NVFP4 all-gather GEMM fusion for AsyncTP
author: baonudesifeizhai
date: '2026-05-10'
url: https://github.com/vllm-project/vllm/pull/41882
source_category: upstream-code
architectures:
- sm100
tags:
- FlashInfer
- blackwell
- cutlass
- fp4
- fp8
- gemm_quant
- memory_primitives
- nvfp4
techniques:
- fine-grained-quantization
- kernel-fusion
hardware_features:
- blackwell
- fp4
- fp8
- nvfp4
kernel_types:
- gemm
- memory
languages:
- cute-dsl
captured_at: '2026-05-16'
status: merged
merge_sha: bc5fdc1e6a718aec4b76b47b69ec5e7cb3c2412a
inclusion_reason: Inspect scale layout, accumulator type, tile/schedule choice, epilogue fusion, and partial-tile guards before deriving a candidate.
changed_paths:
- tests/compile/correctness_e2e/test_async_tp.py
- tests/compile/correctness_e2e/test_sequence_parallel.py
- tests/compile/fullgraph/test_toy_llama.py
- tests/compile/fusions_e2e/test_tp2_async_tp.py
- vllm/compilation/passes/fusion/collective_fusion.py
- vllm/compilation/passes/fusion/sequence_parallelism.py
- vllm/utils/flashinfer.py
artifact_dir: evidence/pull-bundles/vllm/gh-41882
head_ref_oid: b3fdf4f3aec213321515bdd0020eb3f4842239ab
---
# Add NVFP4 all-gather GEMM fusion for AsyncTP

- Repository: `vllm-project/vllm`
- PR: [41882](https://github.com/vllm-project/vllm/pull/41882)
- 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

- `tests/compile/correctness_e2e/test_async_tp.py`
- `tests/compile/correctness_e2e/test_sequence_parallel.py`
- `tests/compile/fullgraph/test_toy_llama.py`
- `tests/compile/fusions_e2e/test_tp2_async_tp.py`
- `vllm/compilation/passes/fusion/collective_fusion.py`
- `vllm/compilation/passes/fusion/sequence_parallelism.py`
- `vllm/utils/flashinfer.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-41882`
