When we turn on vsx it should also turn on altivec explicitly, same
with disabling it as well as disabling all vsx specific features when
turning off altivec.

Fixes PR32663.

llvm-svn: 300395
diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index 18f503d..a457f6d 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -1548,28 +1548,30 @@
 
 void PPCTargetInfo::setFeatureEnabled(llvm::StringMap<bool> &Features,
                                       StringRef Name, bool Enabled) const {
-  // If we're enabling direct-move or power8-vector go ahead and enable vsx
-  // as well. Do the inverse if we're disabling vsx. We'll diagnose any user
-  // incompatible options.
   if (Enabled) {
-    if (Name == "direct-move" ||
-        Name == "power8-vector" ||
-        Name == "float128" ||
-        Name == "power9-vector") {
-      // power9-vector is really a superset of power8-vector so encode that.
-      Features[Name] = Features["vsx"] = true;
-      if (Name == "power9-vector")
-        Features["power8-vector"] = true;
-    } else {
-      Features[Name] = true;
-    }
+    // If we're enabling any of the vsx based features then enable vsx and
+    // altivec. We'll diagnose any problems later.
+    bool FeatureHasVSX = llvm::StringSwitch<bool>(Name)
+                             .Case("vsx", true)
+                             .Case("direct-move", true)
+                             .Case("power8-vector", true)
+                             .Case("power9-vector", true)
+                             .Case("float128", true)
+                             .Default(false);
+    if (FeatureHasVSX)
+      Features["vsx"] = Features["altivec"] = true;
+    if (Name == "power9-vector")
+      Features["power8-vector"] = true;
+    Features[Name] = true;
   } else {
-    if (Name == "vsx") {
-      Features[Name] = Features["direct-move"] = Features["power8-vector"] =
+    // If we're disabling altivec or vsx go ahead and disable all of the vsx
+    // features.
+    if ((Name == "altivec") || (Name == "vsx"))
+      Features["vsx"] = Features["direct-move"] = Features["power8-vector"] =
           Features["float128"] = Features["power9-vector"] = false;
-    } else {
-      Features[Name] = false;
-    }
+    if (Name == "power8-vector")
+      Features["power9-vector"] = false;
+    Features[Name] = false;
   }
 }
 
diff --git a/clang/test/Preprocessor/predefined-arch-macros.c b/clang/test/Preprocessor/predefined-arch-macros.c
index 5252d2c..a0eb8cb 100644
--- a/clang/test/Preprocessor/predefined-arch-macros.c
+++ b/clang/test/Preprocessor/predefined-arch-macros.c
@@ -1957,6 +1957,14 @@
 // End X86/GCC/Linux tests ------------------
 
 // Begin PPC/GCC/Linux tests ----------------
+// Check that VSX also turns on altivec.
+// RUN: %clang -mvsx -E -dM %s -o - 2>&1 \
+// RUN:     -target powerpc-unknown-linux \
+// RUN:   | FileCheck -match-full-lines %s -check-prefix=CHECK_PPC_VSX_M32
+//
+// CHECK_PPC_VSX_M32: #define __ALTIVEC__ 1
+// CHECK_PPC_VSX_M32: #define __VSX__ 1
+//
 // RUN: %clang -mvsx -E -dM %s -o - 2>&1 \
 // RUN:     -target powerpc64-unknown-linux \
 // RUN:   | FileCheck -match-full-lines %s -check-prefix=CHECK_PPC_VSX_M64