[llvm] [NVPTX] Add Volta Atomic SequentiallyConsistent Load and Store Operations (PR #98551)

[via llvm-commits]

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@@ -820,68 +845,76 @@ static unsigned int getCodeMemorySemantic(MemSDNode *N,
       (CodeAddrSpace == NVPTX::PTXLdStInstCode::GENERIC ||
        CodeAddrSpace == NVPTX::PTXLdStInstCode::GLOBAL ||
        CodeAddrSpace == NVPTX::PTXLdStInstCode::SHARED);
+  if (!AddrGenericOrGlobalOrShared)
+    return NVPTX::Ordering::NotAtomic;
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gonzalobg wrote:

Right now, according to the PTX spec, doing a `volatile` of a `.const` is undefined behavior. 
We should probably fix that in the spec, the PTX implementation, and once we add the `.const` and `.param` tests, update all of this as needed.

https://github.com/llvm/llvm-project/pull/98551