microsoft / microsoft/DirectXShaderCompiler
[SPIR-V] SPV_EXT_descriptor_heap RasterizerOrdered flag lost on heap buffer alias re-derivation, suppressing ROV interlock
Nobody has claimed this yet.
- Dominant language
- C++
- Stars
- 3.7k
- Forks
- 900
- Avg merge
- 2d 11h
- Merged PRs (30d)
- 44
Description
Description
When a heap buffer alias pointer is re-derived in emitDescriptorHeapBufferPointer (SpirvEmitter.cpp), the new SpirvInstruction does not copy the RasterizerOrdered flag set on the original pointer in emitDescriptorHeapBufferAccess. Accesses through a local RasterizerOrderedStructuredBuffer or RasterizerOrderedByteAddressBuffer alias therefore do not cause SpirvBuilder to emit the required begin/end invocation interlock. This is a silent correctness bug.
Fix
Add bufferDataPtr->setRasterizerOrdered(isRasterizerOrderedView(decl->getType())) after restoring the storage class and layout rule on the re-derived pointer.
References
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start in SpirvEmitter.cpp at emitDescriptorHeapBufferPointer and compare it with emitDescriptorHeapBufferAccess, where RasterizerOrdered is set on the original pointer. Verify the re-derived pointer preserves that flag after storage class and layout restoration. Done means local RasterizerOrderedStructuredBuffer and RasterizerOrderedByteAddressBuffer aliases cause SpirvBuilder to emit the required begin/end invocation interlock.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- cpp
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 2/5
- Estimated time
- 1-3 hours
- Activity status
- Active
- Clarity
- Clearly specified
- Newbie friendliness
- 85/100