[clang] [llvm] [NVPTX] Add NVVMUpgradeAnnotations pass to cleanup legacy annotations (PR #119261)

[Alex MacLean via llvm-commits]

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@@ -1270,77 +1270,21 @@ exit:
 ; MODULE: attributes #[[ATTR1:[0-9]+]] = { convergent nocallback nounwind }
 ; MODULE: attributes #[[ATTR2:[0-9]+]] = { convergent nocallback nofree nounwind willreturn }
 ; MODULE: attributes #[[ATTR3:[0-9]+]] = { nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: write) }
-; MODULE: attributes #[[ATTR4]] = { "kernel" }
-; MODULE: attributes #[[ATTR5]] = { nosync memory(none) }
+; MODULE: attributes #[[ATTR4]] = { "kernel" "nvvm.kernel" }
+; MODULE: attributes #[[ATTR5]] = { "kernel" }
+; MODULE: attributes #[[ATTR6]] = { nosync memory(none) }
 ;.
 ; CGSCC: attributes #[[ATTR0]] = { "llvm.assume"="ompx_aligned_barrier" }
 ; CGSCC: attributes #[[ATTR1:[0-9]+]] = { convergent nocallback nounwind }
 ; CGSCC: attributes #[[ATTR2:[0-9]+]] = { convergent nocallback nofree nounwind willreturn }
 ; CGSCC: attributes #[[ATTR3:[0-9]+]] = { nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: write) }
-; CGSCC: attributes #[[ATTR4]] = { "kernel" }
-; CGSCC: attributes #[[ATTR5]] = { nosync memory(none) }
+; CGSCC: attributes #[[ATTR4]] = { "kernel" "nvvm.kernel" }
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AlexMaclean wrote:

The problem is that OpenMP seems to need to be able to draw a distinction between OpenMP kernels and nvvm kernels. For example here it seems like OpenMP only wants to look at "kernel" not "nvvm.kernel". As a result it seems like these attributes cannot be easily unified. 
https://github.com/llvm/llvm-project/blob/c835b48a4d72227b174bcd86f071238a1583803a/llvm/lib/Transforms/IPO/OpenMPOpt.cpp#L5932-L5938

https://github.com/llvm/llvm-project/pull/119261