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diff --git a/include/llvm/Support/SlowOperationInformer.h b/include/llvm/Support/SlowOperationInformer.h
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+++ b/include/llvm/Support/SlowOperationInformer.h
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+//===- llvm/Support/SlowOperationInformer.h - Keep user informed *- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a simple object which can be used to let the user know what
+// is going on when a slow operation is happening, and gives them the ability to
+// cancel it.  Potentially slow operations can stack allocate one of these
+// objects, and periodically call the "progress" method to update the progress
+// bar.  If the operation takes more than 1 second to complete, the progress bar
+// is automatically shown and updated.  As such, the slow operation should not
+// print stuff to the screen, and should not be confused if an extra line
+// appears on the screen (ie, the cursor should be at the start of the line).
+//
+// If the user presses CTRL-C during the operation, the next invocation of the
+// progress method return true indicating that the operation was cancelled.
+//
+// Because SlowOperationInformers fiddle around with signals, they cannot be
+// nested, and interact poorly with threads.  The SIGALRM handler is set back to
+// SIGDFL, but the SIGINT signal handler is restored when the
+// SlowOperationInformer is destroyed.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_SLOW_OPERATION_INFORMER_H
+#define LLVM_SUPPORT_SLOW_OPERATION_INFORMER_H
+
+#include <string>
+#include <cassert>
+#include "llvm/Support/DataTypes.h"
+
+namespace llvm {
+  class SlowOperationInformer {
+    std::string OperationName;
+    unsigned LastPrintAmount;
+
+    SlowOperationInformer(const SlowOperationInformer&);   // DO NOT IMPLEMENT
+    void operator=(const SlowOperationInformer&);          // DO NOT IMPLEMENT
+  public:
+    SlowOperationInformer(const std::string &Name);
+    ~SlowOperationInformer();
+
+    /// progress - Clients should periodically call this method when they can
+    /// handle cancellation.  The Amount variable should indicate how far
+    /// along the operation is, given in 1/10ths of a percent (in other words,
+    /// Amount should range from 0 to 1000).  If the user cancels the operation,
+    /// this returns true, false otherwise.
+    bool progress(unsigned Amount);
+
+    /// progress - Same as the method above, but this performs the division for
+    /// you, and helps you avoid overflow if you are dealing with largish
+    /// numbers.
+    bool progress(unsigned Current, unsigned Maximum) {
+      assert(Maximum != 0 &&
+             "Shouldn't be doing work if there is nothing to do!");
+      return progress(Current*uint64_t(1000UL)/Maximum);
+    }
+  };
+} // end namespace llvm
+
+#endif /* SLOW_OPERATION_INFORMER_H */