[None][feat] Support DeepGEMM swap-AB on sm100

[Barry-Delaney]

This PR enables swap AB as an optional tactic for sm100 FP8 blockwise GEMM.

Summary by CodeRabbit

• New Features

  • Enabled an additional tactic for FP8 GEMM that can automatically swap A/B operands when beneficial, expanding kernel choices for potential performance gains on supported GPUs. No API changes required.

• Chores

  • Updated the DeepGEMM submodule to a new repository and branch to align with recent optimizations and ensure compatibility with the expanded FP8 GEMM tactics.

[coderabbitai]

📝 Walkthrough

Walkthrough

Updates .gitmodules to point 3rdparty/DeepGEMM at a different repository and branch, and extends fp8_swap_ab_gemm in torch_custom_ops.py to accept tactics [0,1], branching at runtime to call fp8_gemm_nt (no swap) or fp8_gemm_ntt (swap) based on the tactic.

Changes

Cohort / File(s)	Summary of Changes
Submodule config update .gitmodules	Changed submodule 3rdparty/DeepGEMM URL from https://github.com/deepseek-ai/DeepGEMM.git to https://github.com/ruoqianguo/DeepGEMM.git; added branch dev/ruoqiang/swapab_sm100.
FP8 swap-AB GEMM tactic handling tensorrt_llm/_torch/custom_ops/torch_custom_ops.py	Expanded valid tactics from [0] to [0, 1]; forward now checks tactic and calls fp8_gemm_nt when tactic==0 (no swap) or fp8_gemm_ntt when tactic==1 (swap); introduces swap_ab derived from tactic.

Sequence Diagram(s)

sequenceDiagram
  autonumber
  participant Caller
  participant Op as fp8_swap_ab_gemm
  participant NT as fp8_gemm_nt
  participant NTT as fp8_gemm_ntt

  Caller->>Op: forward(A, B, tactic)
  alt tactic == 1 (swap AB)
    Note right of Op #f0f4ff: swap_ab = true
    Op->>NTT: compute with AB-swapped kernel
    NTT-->>Op: result
  else tactic == 0 (no swap)
    Note right of Op #f0f4ff: swap_ab = false
    Op->>NT: compute with standard kernel
    NT-->>Op: result
  end
  Op-->>Caller: output

Loading

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• [None][feat] Apply AutoTuner to fp8_block_scale_deep_gemm to trigger JIT ahead of time. #7113 — Modifies the same FP8 “swap AB” GEMM path and related op/tuning logic.
• [https://nvbugs/5433581][fix] DeepGEMM installation on SBSA #6588 — Also updates the 3rdparty/DeepGEMM submodule configuration.

Suggested reviewers

• litaotju
• yizhang-nv
• QiJune

Tip

🔌 Remote MCP (Model Context Protocol) integration is now available!

Pro plan users can now connect to remote MCP servers from the Integrations page. Connect with popular remote MCPs such as Notion and Linear to add more context to your reviews and chats.

---

📜 Recent review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

💡 Knowledge Base configuration:

• MCP integration is disabled by default for public repositories
• Jira integration is disabled by default for public repositories
• Linear integration is disabled by default for public repositories

You can enable these sources in your CodeRabbit configuration.

📥 Commits

Reviewing files that changed from the base of the PR and between 250e268 and 10fc27f.

📒 Files selected for processing (2)

• .gitmodules (1 hunks)
• tensorrt_llm/_torch/custom_ops/torch_custom_ops.py (2 hunks)

🚧 Files skipped from review as they are similar to previous changes (2)

• .gitmodules
• tensorrt_llm/_torch/custom_ops/torch_custom_ops.py

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (1)

• GitHub Check: Pre-commit Check

✨ Finishing Touches

• 📝 Generate Docstrings

🧪 Generate unit tests

• Create PR with unit tests
• Post copyable unit tests in a comment

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

🪧 Tips

Chat

There are 3 ways to chat with CodeRabbit:

• Review comments: Directly reply to a review comment made by CodeRabbit. Example:
  • I pushed a fix in commit <commit_id>, please review it.
  • Open a follow-up GitHub issue for this discussion.
• Files and specific lines of code (under the "Files changed" tab): Tag @coderabbit in a new review comment at the desired location with your query.
• PR comments: Tag @coderabbit in a new PR comment to ask questions about the PR branch. For the best results, please provide a very specific query, as very limited context is provided in this mode. Examples:
  • @coderabbit gather interesting stats about this repository and render them as a table. Additionally, render a pie chart showing the language distribution in the codebase.
  • @coderabbit read the files in the src/scheduler package and generate a class diagram using mermaid and a README in the markdown format.

Support

Need help? Create a ticket on our support page for assistance with any issues or questions.

CodeRabbit Commands (Invoked using PR/Issue comments)

Type @coderabbit help to get the list of available commands.

Other keywords and placeholders

• Add @coderabbit ignore or @coderabbitai ignore anywhere in the PR description to prevent this PR from being reviewed.
• Add @coderabbit summary or @coderabbitai summary to generate the high-level summary at a specific location in the PR description.
• Add @coderabbit or @coderabbitai title anywhere in the PR title to generate the title automatically.

Status, Documentation and Community

• Visit our Status Page to check the current availability of CodeRabbit.
• Visit our Documentation for detailed information on how to use CodeRabbit.
• Join our Discord Community to get help, request features, and share feedback.
• Follow us on X/Twitter for updates and announcements.

[Barry-Delaney]

/bot run

[tensorrt-cicd]

PR_Github #16935 [ run ] triggered by Bot

[tensorrt-cicd]

PR_Github #16935 [ run ] completed with state SUCCESS
/LLM/main/L0_MergeRequest_PR pipeline #12721 completed with status: 'FAILURE'

[Barry-Delaney]

/bot run

[tensorrt-cicd]

PR_Github #16953 [ run ] triggered by Bot

[tensorrt-cicd]

PR_Github #16953 [ run ] completed with state FAILURE