Index: cfe/trunk/lib/Basic/Targets.cpp
===================================================================
--- cfe/trunk/lib/Basic/Targets.cpp
+++ cfe/trunk/lib/Basic/Targets.cpp
@@ -3351,6 +3351,12 @@
              Name == "avx512vbmi" || Name == "avx512ifma") {
     if (Enabled)
       setSSELevel(Features, AVX512F, Enabled);
+    // Enable BWI instruction if VBMI is being enabled.
+    if (Name == "avx512vbmi" && Enabled)
+      Features["avx512bw"] = true;
+    // Also disable VBMI if BWI is being disabled.
+    if (Name == "avx512bw" && !Enabled)
+      Features["avx512vbmi"] = false;
   } else if (Name == "fma") {
     if (Enabled)
       setSSELevel(Features, AVX, Enabled);
Index: cfe/trunk/test/Preprocessor/x86_target_features.c
===================================================================
--- cfe/trunk/test/Preprocessor/x86_target_features.c
+++ cfe/trunk/test/Preprocessor/x86_target_features.c
@@ -196,6 +196,7 @@
 // RUN: %clang -target i386-unknown-unknown -march=atom -mavx512vbmi -x c -E -dM -o - %s | FileCheck -match-full-lines --check-prefix=AVX512VBMI %s
 
 // AVX512VBMI: #define __AVX2__ 1
+// AVX512VBMI: #define __AVX512BW__ 1
 // AVX512VBMI: #define __AVX512F__ 1
 // AVX512VBMI: #define __AVX512VBMI__ 1
 // AVX512VBMI: #define __AVX__ 1
@@ -208,6 +209,11 @@
 // AVX512VBMI: #define __SSE__ 1
 // AVX512VBMI: #define __SSSE3__ 1
 
+// RUN: %clang -target i386-unknown-unknown -march=atom -mavx512vbmi -mno-avx512bw -x c -E -dM -o - %s | FileCheck -match-full-lines --check-prefix=AVX512VBMINOAVX512BW %s
+
+// AVX512VBMINOAVX512BW-NOT: #define __AVX512BW__ 1
+// AVX512VBMINOAVX512BW-NOT: #define __AVX512VBMI__ 1
+
 // RUN: %clang -target i386-unknown-unknown -march=atom -msse4.2 -x c -E -dM -o - %s | FileCheck -match-full-lines --check-prefix=SSE42POPCNT %s
 
 // SSE42POPCNT: #define __POPCNT__ 1