[CPU] Fix Alibaba-NLP accuracy issue

[liubo-intel]

Details:

• Fix Alibaba-NLP accuracy issue: avoid fusing MLP with unmatched VariadicSplit output ports

Tickets:

• CVS-175027

[Copilot]

Pull Request Overview

This PR fixes an accuracy issue in the Alibaba-NLP model by adding validation to the MLP fusion pass. The fix ensures that the gate (activation) branch and up branch are correctly positioned as the first and second inputs of the Multiply node respectively before allowing fusion.

Key changes:

• Added input validation logic to verify the gate branch is connected to input0 and the up branch to input1
• Prevents incorrect fusion when VariadicSplit output ports are mismatched

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[yuxu42]

Hi @chenhu-wang could you please take a review? Thanks!

[xuchen-intel]

Please add corresponding subgraph tests to ensure the expected un-fusing behavior is conducted correctly.

[liubo-intel]

Please add corresponding subgraph tests to ensure the expected un-fusing behavior is conducted correctly.

Done

[Copilot]

Pull Request Overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

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