[llvm-branch-commits] [llvm] [DirectX] Updating DXContainer documentation to add Root Descriptors (PR #129759)

[Finn Plummer via llvm-branch-commits]

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@@ -497,3 +497,49 @@ signature and passed to the shader without requiring a constant buffer resource:
 #. **Num32BitValues**: The number of 32-bit values included in this constant buffer.
 
 Root constants provide a fast way to pass small amounts of data directly to the shader without the overhead of creating and binding a constant buffer resource.
+
+Root Descriptor
+~~~~~~~~~~~~~~~
+
+Root descriptors provide a direct mechanism for binding individual resources to shader stages in the Direct3D 12 
+rendering pipeline. They represent a critical interface for efficient resource management, allowing applications 
+to specify how shader stages access specific GPU resources.
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inbelic wrote:

Imo, this strays away from the `what and how` tone throughout this document and into `why`. I think the previous pr did a good job of keeping that tone, which I presume is what we would like. 

https://github.com/llvm/llvm-project/pull/129759