[llvm] [RFC] Memory Model Relaxation Annotations (PR #78569)

[Pierre van Houtryve via llvm-commits]

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@@ -793,13 +794,19 @@ Instruction *llvm::propagateMetadata(Instruction *Inst, ArrayRef<Value *> VL) {
   for (auto Kind : {LLVMContext::MD_tbaa, LLVMContext::MD_alias_scope,
                     LLVMContext::MD_noalias, LLVMContext::MD_fpmath,
                     LLVMContext::MD_nontemporal, LLVMContext::MD_invariant_load,
-                    LLVMContext::MD_access_group}) {
+                    LLVMContext::MD_access_group, LLVMContext::MD_mmra}) {
     MDNode *MD = I0->getMetadata(Kind);
-
     for (int J = 1, E = VL.size(); MD && J != E; ++J) {
       const Instruction *IJ = cast<Instruction>(VL[J]);
       MDNode *IMD = IJ->getMetadata(Kind);
+
       switch (Kind) {
+      case LLVMContext::MD_mmra: {
+        auto Tags = MMRAMetadata(dyn_cast_or_null<MDTuple>(MD));
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Pierre-vh wrote:

> I get the impression that the MMRAMetadata helper class can be moved to the cpp file if all exposes APIs use only MDNode.

No, it's the API used by emitters to create MMRAs (e.g. Clang) and by consumers to parse it (e.g. SIMemoryLegalizer)

https://github.com/llvm/llvm-project/pull/78569