[llvm] [llvm][opt][Transforms] Preserve AMDGPU atomic metadata (PR #140314)

[Alex Voicu via llvm-commits]

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@@ -3303,6 +3303,12 @@ static void combineMetadata(Instruction *K, const Instruction *J,
                             bool DoesKMove, bool AAOnly = false) {
   SmallVector<std::pair<unsigned, MDNode *>, 4> Metadata;
   K->getAllMetadataOtherThanDebugLoc(Metadata);
+
+  const unsigned AMDGPUMD[] = {
+      K->getContext().getMDKindID("amdgpu.no.fine.grained.memory"),
+      K->getContext().getMDKindID("amdgpu.no.remote.memory"),
+      K->getContext().getMDKindID("amdgpu.ignore.denormal.mode")};
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AlexVlx wrote:

Possibly, but there's no other example of target specific MD in the fixed enum. It's also not quite clear where else we could handle these (if you have something in mind, please share). I will re-factor this a bit anyway because it's incomplete (we're missing cases where the replaces Instr carries the MD).

https://github.com/llvm/llvm-project/pull/140314