add sliding window support for webgpu gqa

[guschmue]

No description provided.

[Copilot]

Pull Request Overview

Adds support for a sliding window mask in the GPU-based group query attention (GQA) softmax shader, allowing attention to be constrained to a local window of past tokens.

• Propagate a new local_window_size parameter through ComputeInternal, ApplyAttention, and ComputeInPlaceSoftmax.
• Extend InPlaceSoftmaxProgram to accept local_window_size and emit conditional shader code for sliding-window masking.
• Update function signatures and uniform variable setup to include the new window size parameter.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
contrib_ops/webgpu/bert/group_query_attention.cc	Added local_window_size_ guard for FlashAttention and pass it to ApplyAttention.
contrib_ops/webgpu/bert/attention_common.h	Extended ApplyAttention signature to accept local_window_size.
contrib_ops/webgpu/bert/attention.h	Updated InPlaceSoftmaxProgram constructor and added local_window_size_ field.
contrib_ops/webgpu/bert/attention.cc	Injected sliding-window logic into shader code and passed local_window_size through to the program.

Comments suppressed due to low confidence (2)

onnxruntime/contrib_ops/webgpu/bert/attention.cc:228

• [nitpick] Consider adding unit or integration tests to cover the new sliding window behavior in InPlaceSoftmaxProgram to ensure correctness under various window sizes, including edge cases like window size zero or larger than sequence length.

  bool has_sliding_window = local_window_size_ != -1;

onnxruntime/contrib_ops/webgpu/bert/group_query_attention.cc:199

• [nitpick] Align the indentation for this condition with the other conditions in the if statement to improve readability (e.g., match the two-space indent used for head_sink == nullptr).

      local_window_size_ == -1 &&

[snnn]

Hi there! We haven't cut the release branch for this version yet, so I'm removing the release:1.23.0 label for now to keep things tidy. Thanks so much for your contribution! We'll make sure this gets included when the release is prepared. 🤖