---
id: pr-flash-attention-2251
repo: Dao-AILab/flash-attention
pr: 2251
title: '[Cute] Handle window_size=(-1, -1) for non-local attention'
author: henrylhtsang
date: '2026-02-23'
url: https://github.com/Dao-AILab/flash-attention/pull/2251
source_category: upstream-code
architectures:
- sm100
tags:
- attention
techniques: []
hardware_features: []
kernel_types:
- attention
languages:
- cute-dsl
captured_at: '2026-05-16'
status: merged
merge_sha: 5678dd909aca97f925957dab716022046fb1e44f
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- flash_attn/cute/interface.py
artifact_dir: evidence/pull-bundles/flash-attention/gh-2251
head_ref_oid: 504bbe663382a9e53f86240c46d2d2bb3499d551
---
# [Cute] Handle window_size=(-1, -1) for non-local attention

- Repository: `Dao-AILab/flash-attention`
- PR: [2251](https://github.com/Dao-AILab/flash-attention/pull/2251)
- 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/cute/interface.py`

## Evidence Bundle

`evidence/pull-bundles/flash-attention/gh-2251`
