Index: clang/include/clang/Basic/TargetCXXABI.h
===================================================================
--- clang/include/clang/Basic/TargetCXXABI.h
+++ clang/include/clang/Basic/TargetCXXABI.h
@@ -109,6 +109,12 @@
     ///   - constructors and destructors return 'this', as in ARM.
     Fuchsia,
 
+    /// The XL ABI is a modified version of the Itanium ABI.
+    ///
+    /// The relevant changes from the Itanium ABI are:
+    ///   - static initialization is adjusted to use sinit and sterm functions;
+    XL,
+
     /// The Microsoft ABI is the ABI used by Microsoft Visual Studio (and
     /// compatible compilers).
     ///
@@ -148,6 +154,7 @@
     case WatchOS:
     case GenericMIPS:
     case WebAssembly:
+    case XL:
       return true;
 
     case Microsoft:
@@ -168,6 +175,7 @@
     case WatchOS:
     case GenericMIPS:
     case WebAssembly:
+    case XL:
       return false;
 
     case Microsoft:
@@ -202,6 +210,7 @@
     case iOS64:
     case WatchOS:
     case Microsoft:
+    case XL:
       return true;
     }
     llvm_unreachable("bad ABI kind");
@@ -278,6 +287,7 @@
     case iOS:   // old iOS compilers did not follow this rule
     case Microsoft:
     case GenericMIPS:
+    case XL:
       return true;
     }
     llvm_unreachable("bad ABI kind");
@@ -315,6 +325,7 @@
     case GenericARM:
     case iOS:
     case GenericMIPS:
+    case XL:
       return UseTailPaddingUnlessPOD03;
 
     // iOS on ARM64 and WebAssembly use the C++11 POD rules.  They do not honor
Index: clang/lib/AST/ASTContext.cpp
===================================================================
--- clang/lib/AST/ASTContext.cpp
+++ clang/lib/AST/ASTContext.cpp
@@ -874,6 +874,7 @@
   case TargetCXXABI::GenericMIPS:
   case TargetCXXABI::GenericItanium:
   case TargetCXXABI::WebAssembly:
+  case TargetCXXABI::XL:
     return CreateItaniumCXXABI(*this);
   case TargetCXXABI::Microsoft:
     return CreateMicrosoftCXXABI(*this);
@@ -10251,6 +10252,7 @@
   case TargetCXXABI::iOS64:
   case TargetCXXABI::WebAssembly:
   case TargetCXXABI::WatchOS:
+  case TargetCXXABI::XL:
     return ItaniumMangleContext::create(*this, getDiagnostics());
   case TargetCXXABI::Microsoft:
     return MicrosoftMangleContext::create(*this, getDiagnostics());
Index: clang/lib/Basic/Targets/OSTargets.h
===================================================================
--- clang/lib/Basic/Targets/OSTargets.h
+++ clang/lib/Basic/Targets/OSTargets.h
@@ -706,6 +706,8 @@
 public:
   AIXTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
       : OSTargetInfo<Target>(Triple, Opts) {
+    this->TheCXXABI.set(TargetCXXABI::XL);
+
     if (this->PointerWidth == 64) {
       this->WCharType = this->UnsignedInt;
     } else {
Index: clang/lib/CodeGen/CodeGenModule.cpp
===================================================================
--- clang/lib/CodeGen/CodeGenModule.cpp
+++ clang/lib/CodeGen/CodeGenModule.cpp
@@ -83,6 +83,7 @@
   case TargetCXXABI::GenericMIPS:
   case TargetCXXABI::GenericItanium:
   case TargetCXXABI::WebAssembly:
+  case TargetCXXABI::XL:
     return CreateItaniumCXXABI(CGM);
   case TargetCXXABI::Microsoft:
     return CreateMicrosoftCXXABI(CGM);
Index: clang/lib/CodeGen/ItaniumCXXABI.cpp
===================================================================
--- clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -516,6 +516,16 @@
   }
   bool canCallMismatchedFunctionType() const override { return false; }
 };
+
+class XLCXXABI final : public ItaniumCXXABI {
+public:
+  explicit XLCXXABI(CodeGen::CodeGenModule &CGM)
+      : ItaniumCXXABI(CGM) {}
+
+  void registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
+                          llvm::FunctionCallee dtor,
+                          llvm::Constant *addr) override;
+};
 }
 
 CodeGen::CGCXXABI *CodeGen::CreateItaniumCXXABI(CodeGenModule &CGM) {
@@ -546,6 +556,9 @@
   case TargetCXXABI::WebAssembly:
     return new WebAssemblyCXXABI(CGM);
 
+  case TargetCXXABI::XL:
+    return new XLCXXABI(CGM);
+
   case TargetCXXABI::GenericItanium:
     if (CGM.getContext().getTargetInfo().getTriple().getArch()
         == llvm::Triple::le32) {
@@ -4407,3 +4420,11 @@
         NormalCleanup, cast<llvm::CatchPadInst>(CGF.CurrentFuncletPad));
   ItaniumCXXABI::emitBeginCatch(CGF, C);
 }
+
+/// Register a global destructor as best as we know how.
+void XLCXXABI::registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
+                                  llvm::FunctionCallee dtor,
+                                  llvm::Constant *addr) {
+  llvm::report_fatal_error("Static initialization has not been implemented on"
+                           " XL ABI yet.");
+}
Index: clang/test/CodeGen/static-init.cpp
===================================================================
--- /dev/null
+++ clang/test/CodeGen/static-init.cpp
@@ -0,0 +1,12 @@
+// RUN: not %clang_cc1 -triple powerpc-ibm-aix-xcoff -S -emit-llvm -x c++ %s \
+// RUN: 2>&1 | FileCheck %s
+
+// RUN: not %clang_cc1 -triple powerpc64-ibm-aix-xcoff -S -emit-llvm -x c++ %s \
+// RUN: 2>&1 | FileCheck %s
+
+struct test {
+  test();
+  ~test();
+} t;
+
+// CHECK: error in backend: Static initialization has not been implemented on XL ABI yet.