diff --git a/lib/Target/X86/X86Subtarget.cpp b/lib/Target/X86/X86Subtarget.cpp
index 3333a3a8856..124c97ac701 100644
--- a/lib/Target/X86/X86Subtarget.cpp
+++ b/lib/Target/X86/X86Subtarget.cpp
@@ -115,8 +115,11 @@ void X86Subtarget::AutoDetectSubtargetFeatures() {
   if (ECX & 0x1)         X86SSELevel = SSE3;
   if ((ECX >> 9)  & 0x1) X86SSELevel = SSSE3;
 
-  X86::GetCpuIDAndInfo(0x80000001, &EAX, &EBX, &ECX, &EDX);
-  HasX86_64 = (EDX >> 29) & 0x1;
+  if (memcmp(text.c, "GenuineIntel", 12) == 0 ||
+      memcmp(text.c, "AuthenticAMD", 12) == 0) {
+    X86::GetCpuIDAndInfo(0x80000001, &EAX, &EBX, &ECX, &EDX);
+    HasX86_64 = (EDX >> 29) & 0x1;
+  }
 }
 
 static const char *GetCurrentX86CPU() {