---
id: pr-flashinfer-1979
repo: flashinfer-ai/flashinfer
pr: 1979
title: 'feat: Add backend=''auto'' to mm_fp4 and enable autotune for backend=''cudnn'''
author: bkryu
date: '2025-11-21'
url: https://github.com/flashinfer-ai/flashinfer/pull/1979
source_category: upstream-code
architectures:
- sm100
tags:
- fp4
- gemm
techniques: []
hardware_features:
- fp4
kernel_types:
- gemm
languages:
- python
captured_at: '2026-04-27'
status: merged
merge_sha: 0aee7afd1d0db060776333f1274ebc0027d2b71e
inclusion_reason: kernel file changes
changed_paths:
- benchmarks/routines/flashinfer_benchmark_utils.py
- benchmarks/routines/gemm.py
- flashinfer/gemm/gemm_base.py
- flashinfer/utils.py
- tests/gemm/test_mm_fp4.py
- tests/utils/test_decorators.py
head_ref_oid: fe2070b0c98d42bf80b22d6d40aa24824d4bce50
artifact_dir: evidence/pull-bundles/flashinfer/gh-1979
---
# feat: Add backend='auto' to mm_fp4 and enable autotune for backend='cudnn'

- Repository: `flashinfer-ai/flashinfer`
- PR: [1979](https://github.com/flashinfer-ai/flashinfer/pull/1979)
- Decision: `kernel file changes`
- Reason: kernel file changes

## Changed Paths

- `benchmarks/routines/flashinfer_benchmark_utils.py`
- `benchmarks/routines/gemm.py`
- `flashinfer/gemm/gemm_base.py`
- `flashinfer/utils.py`
- `tests/gemm/test_mm_fp4.py`
- `tests/utils/test_decorators.py`

## Evidence Bundle

`evidence/pull-bundles/flashinfer/gh-1979`
