[Clang][AMDGPU] Stop defaulting to one-as for all atomic scopes (llvm#120095) (llvm#1536)

Author: vikramRH

clang/lib/CodeGen/Targets/AMDGPU.cpp

@@ -530,7 +530,11 @@ AMDGPUTargetCodeGenInfo::getLLVMSyncScopeID(const LangOptions &LangOpts,
     break;
   }
 
-  if (Ordering != llvm::AtomicOrdering::SequentiallyConsistent) {
+  // OpenCL assumes by default that atomic scopes are per-address space for
+  // non-sequentially consistent operations.
+  if (Scope >= SyncScope::OpenCLWorkGroup &&
+      Scope <= SyncScope::OpenCLSubGroup &&
+      Ordering != llvm::AtomicOrdering::SequentiallyConsistent) {
     if (!Name.empty())
       Name = Twine(Twine(Name) + Twine("-")).str();