Index: cfe/trunk/lib/Basic/Targets/X86.cpp
===================================================================
--- cfe/trunk/lib/Basic/Targets/X86.cpp
+++ cfe/trunk/lib/Basic/Targets/X86.cpp
@@ -175,7 +175,8 @@
     setFeatureEnabledImpl(Features, "avx512bw", true);
     setFeatureEnabledImpl(Features, "avx512vl", true);
     setFeatureEnabledImpl(Features, "pku", true);
-    setFeatureEnabledImpl(Features, "clwb", true);
+    if (Kind != CK_Cannonlake) // CNL inherits all SKX features, except CLWB
+      setFeatureEnabledImpl(Features, "clwb", true);
     LLVM_FALLTHROUGH;
   case CK_SkylakeClient:
     setFeatureEnabledImpl(Features, "xsavec", true);
Index: cfe/trunk/test/Preprocessor/predefined-arch-macros.c
===================================================================
--- cfe/trunk/test/Preprocessor/predefined-arch-macros.c
+++ cfe/trunk/test/Preprocessor/predefined-arch-macros.c
@@ -974,7 +974,7 @@
 // CHECK_CNL_M32: #define __BMI2__ 1
 // CHECK_CNL_M32: #define __BMI__ 1
 // CHECK_CNL_M32: #define __CLFLUSHOPT__ 1
-// CHECK_CNL_M32: #define __CLWB__ 1
+// CHECK_CNL_M32-NOT: #define __CLWB__ 1
 // CHECK_CNL_M32: #define __F16C__ 1
 // CHECK_CNL_M32: #define __FMA__ 1
 // CHECK_CNL_M32: #define __LZCNT__ 1
@@ -1022,7 +1022,7 @@
 // CHECK_CNL_M64: #define __BMI2__ 1
 // CHECK_CNL_M64: #define __BMI__ 1
 // CHECK_CNL_M64: #define __CLFLUSHOPT__ 1
-// CHECK_CNL_M64: #define __CLWB__ 1
+// CHECK_CNL_M64-NOT: #define __CLWB__ 1
 // CHECK_CNL_M64: #define __F16C__ 1
 // CHECK_CNL_M64: #define __FMA__ 1
 // CHECK_CNL_M64: #define __LZCNT__ 1