---
id: pr-flash-attention-2343
repo: Dao-AILab/flash-attention
pr: 2343
title: '[ROCm] Auto-detect Triton backend if C++ extension is missing'
author: Soddentrough
date: '2026-03-18'
url: https://github.com/Dao-AILab/flash-attention/pull/2343
source_category: upstream-code
architectures:
- sm90
tags:
- hopper
techniques: []
hardware_features:
- hopper
kernel_types:
- attention
languages:
- triton
captured_at: '2026-05-16'
status: merged
merge_sha: 0f82fead0b2d59f6390c62a1d74e927159bc5a7b
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- flash_attn/flash_attn_interface.py
- hopper/flash_attn_interface.py
artifact_dir: evidence/pull-bundles/flash-attention/gh-2343
head_ref_oid: 4bc6cf506d54baaee3fee2fa96aa3b380cba2f8e
---
# [ROCm] Auto-detect Triton backend if C++ extension is missing

- Repository: `Dao-AILab/flash-attention`
- PR: [2343](https://github.com/Dao-AILab/flash-attention/pull/2343)
- Decision: `Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.`
- Reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.

## Changed Paths

- `flash_attn/flash_attn_interface.py`
- `hopper/flash_attn_interface.py`

## Evidence Bundle

`evidence/pull-bundles/flash-attention/gh-2343`
