diff --git a/llvm/lib/Target/X86/X86Subtarget.cpp b/llvm/lib/Target/X86/X86Subtarget.cpp
index 463b47f14ff4..610bf1da432b 100644
--- a/llvm/lib/Target/X86/X86Subtarget.cpp
+++ b/llvm/lib/Target/X86/X86Subtarget.cpp
@@ -241,6 +241,7 @@ X86Subtarget::X86Subtarget(const Module &M, const std::string &FS, bool is64Bit)
   : AsmFlavor(AsmWriterFlavor)
   , PICStyle(PICStyle::None)
   , X86SSELevel(NoMMXSSE)
+  , X863DNowLevel(NoThreeDNow)
   , HasX86_64(false)
   , DarwinVers(0)
   , stackAlignment(8)