2 files changed, 16 insertions, 5 deletions
diff --git a/include/clang/Basic/ObjCRuntime.h b/include/clang/Basic/ObjCRuntime.h
index 10922ed5af..228135d094 100644
--- a/include/clang/Basic/ObjCRuntime.h
+++ b/include/clang/Basic/ObjCRuntime.h
@@ -16,6 +16,7 @@
 #define LLVM_CLANG_OBJCRUNTIME_H
 
 #include "clang/Basic/VersionTuple.h"
+#include "llvm/ADT/Triple.h"
 #include "llvm/Support/ErrorHandling.h"
 
 namespace clang {
@@ -84,6 +85,21 @@ public:
   /// implied behaviors for a "fragile" ABI?
   bool isFragile() const { return !isNonFragile(); }
 
+  /// The default dispatch mechanism to use for the specified architecture
+  bool isLegacyDispatchDefaultForArch(llvm::Triple::ArchType Arch) {
+    // The GNUstep runtime uses a newer dispatch method by default from
+    // version 1.6 onwards
+    if (getKind() == GNUstep && getVersion() >= VersionTuple(1, 6)) {
+      if (Arch == llvm::Triple::arm ||
+          Arch == llvm::Triple::x86 ||
+          Arch == llvm::Triple::x86_64)
+        return false;
+      // Mac runtimes use legacy dispatch everywhere except x86-64
+    } else if (isNeXTFamily() && isNonFragile())
+        return Arch != llvm::Triple::x86_64;
+    return true;
+  }
+
   /// \brief Is this runtime basically of the GNUstep family of runtimes?
   bool isGNUFamily() const {
     switch (getKind()) {
diff --git a/include/clang/Driver/ToolChain.h b/include/clang/Driver/ToolChain.h
index 642d8a4274..ab417bb577 100644
--- a/include/clang/Driver/ToolChain.h
+++ b/include/clang/Driver/ToolChain.h
@@ -149,11 +149,6 @@ public:
   /// -fobjc-nonfragile-abi by default.
   virtual bool IsObjCNonFragileABIDefault() const { return false; }
 
-  /// IsObjCLegacyDispatchDefault - Does this tool chain set
-  /// -fobjc-legacy-dispatch by default (this is only used with the non-fragile
-  /// ABI).
-  virtual bool IsObjCLegacyDispatchDefault() const { return true; }
-
   /// UseObjCMixedDispatchDefault - When using non-legacy dispatch, should the
   /// mixed dispatch method be used?
   virtual bool UseObjCMixedDispatch() const { return false; }