diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -1371,12 +1371,12 @@
     setLibcallName(RTLIB::MULO_I64, nullptr);
   }
 
-  if (!isPPC64)
-    setMaxAtomicSizeInBitsSupported(32);
-  else if (shouldInlineQuadwordAtomics())
+  if (shouldInlineQuadwordAtomics())
     setMaxAtomicSizeInBitsSupported(128);
-  else
+  else if (isPPC64)
     setMaxAtomicSizeInBitsSupported(64);
+  else
+    setMaxAtomicSizeInBitsSupported(32);
 
   setStackPointerRegisterToSaveRestore(isPPC64 ? PPC::X1 : PPC::R1);