Design Meeting Minutes: 2025/04/29

NOTE: Please read the terms of participation (“Terms”) prior to joining the Teams meeting. You joining the Teams meeting with Microsoft indicates your acknowledgement, agreement, and consent to these Terms. If you do not agree to these Terms, please do not join the meeting.

If you intend to contribute code or other copyrightable materials (e.g. written comments, tools, documentation, etc.) to the hlsl specs repository, you are required to sign a Contributor License Agreement (CLA). For details, visit https://cla.microsoft.com.

Administrivia

• No updates

Issues

• No marked issues

PRs

Carried Forward

• [dxil] Proposal to add new debug printf dxil op
  • @pow2clk and @tex3d will review this in more detail.
• [202x] Propose adding vk::SampledTexture* types
  • Ready to merge.
• Add proposal for scalar layout for constant buffers
  • Action Item @llvm-beanz - Move to merge.
• Introduce really rough linalg matrix proposal
  • Action Item: @llvm-beanz to merge
• Rough proposal collecting thoughts on uniformity
  • Action Item: @llvm-beanz to update
• New Proposal: Draft proposal to modify resource typing in HLSL
  • Action item: @llvm-beanz to work with author

Current Business

• [Decl.Init.Agg] Arrays of unknown size
  • Ready for review
• Add an initial proposal for HLSL 202x deprecations
  • Why isn’t uniform propagated to DXIL?
    • @llvm-beanz: I don’t actually know the history. DXC has never done anything with the keyword and we don’t have a representation in DXIL.
    • We do have a larger proposal to address uniformity
    • We should also consider if that proposal needs DXIL and SPIRV changes to preserve information for the backends.
  • ISVs represented in the room did not express any immediate concerns about these deprecations.
• Constant Buffers!
  • Constant buffers language spec - initial draft
  • Constant Buffer Contexts
  • What is the correct relationship between cbuffer and namespace?
    • Some fun cbuffer examples
  • We would like to undesrstand the impact of this change on existing shader codebases.
  • ISVs represented in the room did not express any immediate concerns.

SM 6.9

• Long vector test plan
• Cooperative Vectors Test Plan
• [0029] Update example code to use real API
• [0030][SM6.9] Add list of ops with vector overload
• [0029] Make “input signed op kind"s be “is input unsigned” and booleans
• [0027] Avoid using undef for dx.op.MaybeReorderThread

Other Discussion