[llvm] [SDAG][NVPTX] Cache control metadata support and lowering (PR #204067)

[Kerry McLaughlin via llvm-commits]

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@@ -226,6 +228,9 @@ findSplitPointForStackProtector(MachineBasicBlock *BB,
 /// simpler test.
 LLVM_ABI FPClassTest invertFPClassTestIfSimpler(FPClassTest Test, bool UseFCmp);
 
+LLVM_ABI const MDNode *getMemCacheHintMetadata(const Instruction &I,
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kmclaughlin-arm wrote:

I think there should also be a small comment here to document `getMemCacheHintMetadata`.

https://github.com/llvm/llvm-project/pull/204067