[clang] [llvm] [AMDGPU] Add amdgpu-as MMRA for fences (PR #78572)

[Sameer Sahasrabuddhe via cfe-commits]

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@@ -678,6 +679,59 @@ class SIMemoryLegalizer final : public MachineFunctionPass {
   bool runOnMachineFunction(MachineFunction &MF) override;
 };
 
+static std::array<std::pair<StringLiteral, SIAtomicAddrSpace>, 3> ASNames = {{
+    {"global", SIAtomicAddrSpace::GLOBAL},
+    {"local", SIAtomicAddrSpace::LDS},
+    {"image", SIAtomicAddrSpace::SCRATCH},
+}};
+
+void diagnoseUnknownMMRAASName(const MachineInstr &MI, StringRef AS) {
+  const MachineFunction *MF = MI.getMF();
+  const Function &Fn = MF->getFunction();
+  std::string Str;
+  raw_string_ostream OS(Str);
+  OS << "unknown address space '" << AS << "'; expected one of ";
+  bool IsFirst = true;
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ssahasra wrote:

Use ListSeparator from StringExtras.h

https://github.com/llvm/llvm-project/pull/78572