[ARM] Add -mfpu=none option to the driver.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@191736 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index dd48bc1..ff50169 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -573,8 +573,36 @@
 //
 // FIXME: Centralize feature selection, defaulting shouldn't be also in the
 // frontend target.
-static void getFPUFeatures(const Driver &D, const Arg *A, const ArgList &Args,
-                           std::vector<const char *> &Features) {
+static void getAArch64FPUFeatures(const Driver &D, const Arg *A,
+                                  const ArgList &Args,
+                                  std::vector<const char *> &Features) {
+  StringRef FPU = A->getValue();
+  if (FPU == "fp-armv8") {
+    Features.push_back("+fp-armv8");
+  } else if (FPU == "neon-fp-armv8") {
+    Features.push_back("+fp-armv8");
+    Features.push_back("+neon");
+  } else if (FPU == "crypto-neon-fp-armv8") {
+    Features.push_back("+fp-armv8");
+    Features.push_back("+neon");
+    Features.push_back("+crypto");
+  } else if (FPU == "neon") {
+    Features.push_back("+neon");
+  } else if (FPU == "none") {
+    Features.push_back("-fp-armv8");
+    Features.push_back("-crypto");
+    Features.push_back("-neon");
+  } else
+    D.Diag(diag::err_drv_clang_unsupported) << A->getAsString(Args);
+}
+
+// Handle -mfpu=.
+//
+// FIXME: Centralize feature selection, defaulting shouldn't be also in the
+// frontend target.
+static void getARMFPUFeatures(const Driver &D, const Arg *A,
+                              const ArgList &Args,
+                              std::vector<const char *> &Features) {
   StringRef FPU = A->getValue();
 
   // Set the target features based on the FPU.
@@ -603,6 +631,13 @@
     Features.push_back("+fp-armv8");
   } else if (FPU == "neon") {
     Features.push_back("+neon");
+  } else if (FPU == "none") {
+    Features.push_back("-vfp2");
+    Features.push_back("-vfp3");
+    Features.push_back("-vfp4");
+    Features.push_back("-fp-armv8");
+    Features.push_back("-crypto");
+    Features.push_back("-neon");
   } else
     D.Diag(diag::err_drv_clang_unsupported) << A->getAsString(Args);
 }
@@ -704,7 +739,7 @@
 
   // Honor -mfpu=.
   if (const Arg *A = Args.getLastArg(options::OPT_mfpu_EQ))
-    getFPUFeatures(D, A, Args, Features);
+    getARMFPUFeatures(D, A, Args, Features);
 
   // Setting -msoft-float effectively disables NEON because of the GCC
   // implementation, although the same isn't true of VFP or VFP3.
@@ -1384,7 +1419,7 @@
                                      std::vector<const char *> &Features) {
   // Honor -mfpu=.
   if (const Arg *A = Args.getLastArg(options::OPT_mfpu_EQ))
-    getFPUFeatures(D, A, Args, Features);
+    getAArch64FPUFeatures(D, A, Args, Features);
 }
 
 static void getTargetFeatures(const Driver &D, const llvm::Triple &Triple,