1 files changed, 29 insertions, 8 deletions

diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index ed7bf60c024..270d9941ec8 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -1499,19 +1499,40 @@ void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,
     const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl);
     if (FD && FD->hasAttr<TargetAttr>()) {
       llvm::StringMap<bool> FeatureMap;
-      auto *TD = FD->getAttr<TargetAttr>();
+      const auto *TD = FD->getAttr<TargetAttr>();
 
       // Make a copy of the features as passed on the command line.
       std::vector<std::string> FnFeatures =
           getTarget().getTargetOpts().FeaturesAsWritten;
 
-      std::vector<std::string> &AttrFeatures = TD->getFeatures();
-      std::copy(AttrFeatures.begin(), AttrFeatures.end(),
-                std::back_inserter(FnFeatures));
-
-      if (TD->getCPU() != "")
-	TargetCPU = TD->getCPU();
-
+      // Grab the target attribute string.
+      StringRef FeaturesStr = TD->getFeatures();
+      SmallVector<StringRef, 1> AttrFeatures;
+      FeaturesStr.split(AttrFeatures, ",");
+
+      // Grab the various features and prepend a "+" to turn on the feature to
+      // the backend and add them to our existing set of features.
+      for (auto &Feature : AttrFeatures) {
+        // Go ahead and trim whitespace rather than either erroring or
+        // accepting it weirdly.
+        Feature = Feature.trim();
+
+        // While we're here iterating check for a different target cpu.
+        if (Feature.startswith("arch="))
+          TargetCPU = Feature.split("=").second.trim();
+        else if (Feature.startswith("tune="))
+          // We don't support cpu tuning this way currently.
+          ;
+        else if (Feature.startswith("fpmath="))
+          // TODO: Support the fpmath option this way. It will require checking
+          // overall feature validity for the function with the rest of the
+          // attributes on the function.
+          ;
+        else if (Feature.startswith("no-"))
+          FnFeatures.push_back("-" + Feature.split("-").second.str());
+        else
+          FnFeatures.push_back("+" + Feature.str());
+      }
       // Now populate the feature map, first with the TargetCPU which is either
       // the default or a new one from the target attribute string. Then we'll
       // use the passed in features (FeaturesAsWritten) along with the new ones