diff --git a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
--- a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
+++ b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
@@ -119,6 +119,7 @@
   HasICBT = false;
   HasInvariantFunctionDescriptors = false;
   HasPartwordAtomics = false;
+  HasQuadwordAtomics = false;
   HasDirectMove = false;
   HasHTM = false;
   HasFloat128 = false;