2 files changed, 49 insertions, 0 deletions
diff --git a/include/llvm/Target/TargetMachine.h b/include/llvm/Target/TargetMachine.h
index 6e3fe35..efeb61d 100644
--- a/include/llvm/Target/TargetMachine.h
+++ b/include/llvm/Target/TargetMachine.h
@@ -19,6 +19,7 @@
 
 namespace llvm {
 
+class TargetSubtarget;
 class TargetInstrInfo;
 class TargetInstrDescriptor;
 class TargetJITInfo;
@@ -97,6 +98,13 @@ public:
   virtual const TargetFrameInfo        *getFrameInfo() const { return 0; }
   const TargetData &getTargetData() const { return DataLayout; }
 
+  virtual const TargetSubtarget *getSubtargetImpl() const { return 0; }
+  template<typename STC> STC *getSubtarget() const {
+    assert(getSubtargetImpl() && dynamic_cast<STC*>(getSubtargetImpl()) &&
+           "Not the right kind of subtarget!");
+    return (STC*)getSubtargetImpl();
+  }
+
   /// getRegisterInfo - If register information is available, return it.  If
   /// not, return null.  This is kept separate from RegInfo until RegInfo has
   /// details of graph coloring register allocation removed from it.
diff --git a/include/llvm/Target/TargetSubtarget.h b/include/llvm/Target/TargetSubtarget.h
new file mode 100644
index 0000000..e99afe2
--- /dev/null
+++ b/include/llvm/Target/TargetSubtarget.h
@@ -0,0 +1,41 @@
+//==-- llvm/Target/TargetSubtarget.h - Target Information --------*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Nate Begeman and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file describes the subtarget options of a Target machine.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TARGET_TARGETSUBTARGET_H
+#define LLVM_TARGET_TARGETSUBTARGET_H
+
+namespace llvm {
+
+class Module;
+
+//===----------------------------------------------------------------------===//
+///
+/// TargetSubtarget - Generic base class for all target subtargets.  All
+/// Target-specific options that control code generation and printing should
+/// be exposed through a TargetSubtarget-derived class.
+///
+class TargetSubtarget {
+  TargetSubtarget(const TargetSubtarget&);   // DO NOT IMPLEMENT
+  void operator=(const TargetSubtarget&);  // DO NOT IMPLEMENT
+protected: // Can only create subclasses...
+  /// This constructor initializes the data members to match that 
+  /// of the specified module.
+  ///
+  TargetSubtarget(const Module &M);
+public:
+  virtual ~TargetSubtarget();
+};
+
+} // End llvm namespace
+
+#endif