---
id: pr-flashinfer-2853
repo: flashinfer-ai/flashinfer
pr: 2853
title: 'fix: int32 overflow in `trtllm_fp4_block_scale_moe` causing "Unsupported hidden state scale shape" for EP32+ configs'
author: qiching
date: '2026-03-24'
url: https://github.com/flashinfer-ai/flashinfer/pull/2853
source_category: upstream-code
architectures:
- sm100
tags:
- block-scale
- fp4
- kernel-fusion
- moe
techniques:
- kernel-fusion
hardware_features:
- block-scale
- fp4
kernel_types:
- moe
languages:
- cuda-cpp
captured_at: '2026-04-27'
status: merged
merge_sha: 76790d894b136f9eb7f8262e3b33dba92d3d8768
inclusion_reason: kernel file changes
changed_paths:
- csrc/trtllm_fused_moe_kernel_launcher.cu
head_ref_oid: 69e587e388cb3ae485e60ad731c7b4fe57b1a2d5
artifact_dir: evidence/pull-bundles/flashinfer/gh-2853
---
# fix: int32 overflow in `trtllm_fp4_block_scale_moe` causing "Unsupported hidden state scale shape" for EP32+ configs

- Repository: `flashinfer-ai/flashinfer`
- PR: [2853](https://github.com/flashinfer-ai/flashinfer/pull/2853)
- Decision: `kernel file changes`
- Reason: kernel file changes

## Changed Paths

- `csrc/trtllm_fused_moe_kernel_launcher.cu`

## Evidence Bundle

`evidence/pull-bundles/flashinfer/gh-2853`
