[clang] [llvm] [SPIRV][HLSL] Fix Vulkan-invalid SPIR-V for Interlocked* on groupshared/UAV memory (PR #212663)

[Farzon Lotfi via cfe-commits]

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@@ -310,6 +310,16 @@ static Value *handleElementwiseF32ToF16(CodeGenFunction &CGF,
   llvm_unreachable("Intrinsic F32ToF16 not supported by target architecture");
 }
 
+// Pick the atomic memory scope for an HLSL Interlocked* op by destination:
+// Workgroup for groupshared, Device otherwise (Vulkan forbids CrossDevice).
+static llvm::SyncScope::ID GetInterlockedScope(CodeGenFunction &CGF,
+                                               const LValue &DestLV) {
+  StringRef ScopeName = DestLV.getAddressSpace() == LangAS::hlsl_groupshared
+                            ? "workgroup"
+                            : "device";
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farzonl wrote:

Hmm there is a bit of an established pattern to do stuff like this in `clang/lib/CodeGen/Targets/SPIR.cpp`. If this is SPIRV specfic should it really live here?

https://github.com/llvm/llvm-project/pull/212663