[llvm-branch-commits] [clang] clang/AMDGPU: Set noalias.addrspace metadata on atomicrmw (PR #102462)

[Artem Belevich via llvm-branch-commits]

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@@ -550,6 +551,16 @@ AMDGPUTargetCodeGenInfo::getLLVMSyncScopeID(const LangOptions &LangOpts,
 
 void AMDGPUTargetCodeGenInfo::setTargetAtomicMetadata(
     CodeGenFunction &CGF, llvm::AtomicRMWInst &RMW) const {
+
+  if (RMW.getPointerAddressSpace() == llvm::AMDGPUAS::FLAT_ADDRESS &&
+      CGF.CGM.getLangOpts().threadPrivateMemoryAtomicsAreUndefined()) {
+    llvm::MDBuilder MDHelper(CGF.getLLVMContext());
+    llvm::MDNode *ASRange = MDHelper.createRange(
+        llvm::APInt(32, llvm::AMDGPUAS::PRIVATE_ADDRESS),
+        llvm::APInt(32, llvm::AMDGPUAS::PRIVATE_ADDRESS + 1));
+    RMW.setMetadata(llvm::LLVMContext::MD_noalias_addrspace, ASRange);
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Artem-B wrote:

What's the plan for this metadata? It does not seem to exist or be used for anything yet. 
I do not see it in https://github.com/llvm/llvm-project/blob/6b5308b7924108d63149d7c521f21c5e90da7a09/llvm/include/llvm/IR/FixedMetadataKinds.def#L21

Does this patch miss some changes or depends on other patches?

https://github.com/llvm/llvm-project/pull/102462