---
id: pr-vllm-39547
repo: vllm-project/vllm
pr: 39547
title: '[Perf] Fuse Zero Initializer for FP8 DeepGemm Block Quant Kernel'
author: wzhao18
date: '2026-04-11'
url: https://github.com/vllm-project/vllm/pull/39547
source_category: upstream-code
architectures:
- sm100
tags:
- DeepGEMM
- benchmark_test
- gemm_quant
techniques:
- fine-grained-quantization
hardware_features:
- fp8
kernel_types:
- gemm
languages:
- cuda-cpp
captured_at: '2026-05-16'
status: merged
merge_sha: 59b2f7b64007c6eae7d8ec82cbf1f33500d1ad2d
inclusion_reason: Inspect scale layout, accumulator type, tile/schedule choice, epilogue fusion, and partial-tile guards before deriving a candidate.
changed_paths:
- csrc/libtorch_stable/quantization/w8a8/fp8/per_token_group_quant.cu
- tests/kernels/quantization/test_per_token_group_quant.py
artifact_dir: evidence/pull-bundles/vllm/gh-39547
head_ref_oid: e77a65156662ec5f9f82b9dea0acf8ef329ae953
---
# [Perf] Fuse Zero Initializer for FP8 DeepGemm Block Quant Kernel

- Repository: `vllm-project/vllm`
- PR: [39547](https://github.com/vllm-project/vllm/pull/39547)
- 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

- `csrc/libtorch_stable/quantization/w8a8/fp8/per_token_group_quant.cu`
- `tests/kernels/quantization/test_per_token_group_quant.py`

## Evidence Bundle

`evidence/pull-bundles/vllm/gh-39547`
