New Spiller interface and trivial implementation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72030 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/Spiller.h b/lib/CodeGen/Spiller.h
new file mode 100644
index 0000000..f17a0b5
--- /dev/null
+++ b/lib/CodeGen/Spiller.h
@@ -0,0 +1,32 @@
+//===-- llvm/CodeGen/Spiller.h - Spiller -*- C++ -*------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_SPILLER_H
+#define LLVM_CODEGEN_SPILLER_H
+
+#include <vector>
+
+namespace llvm {
+
+  /// Spiller interface.
+  ///
+  /// Implementations are utility classes which insert spill or remat code on
+  /// demand.
+  class Spiller {
+  public:
+    virtual ~Spiller() = 0;
+    virtual std::vector<class LiveInterval*> spill(class LiveInterval *li) = 0;
+  };
+
+  /// Create and return a spiller object, as specified on the command line.
+  Spiller* createSpiller(class MachineFunction *mf, class LiveIntervals *li,
+                         class VirtRegMap *vrm);
+}
+
+#endif