Subzero: Randomly insert nops.

src/IceRNG.h

 //===- subzero/src/IceRNG.h - Random number generator -----------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares a random number generator.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef SUBZERO_SRC_ICERNG_H
 #define SUBZERO_SRC_ICERNG_H
 
 #include <stdint.h>
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Compiler.h"
 
 namespace Ice {
 
 class RandomNumberGenerator {
 public:
   RandomNumberGenerator(llvm::StringRef Salt);
   uint64_t next(uint64_t Max);
 
 private:
+  RandomNumberGenerator(const RandomNumberGenerator &) LLVM_DELETED_FUNCTION;
+  RandomNumberGenerator &
+  operator=(const RandomNumberGenerator &) LLVM_DELETED_FUNCTION;
+
   uint64_t State;
 };
 
+// This class adds additional random number generator utilities. The
+// reason for the wrapper class is that we want to keep the
+// RandomNumberGenerator interface identical to LLVM's.
+class RandomNumberGeneratorWrapper {
+public:
+  uint64_t next(uint64_t Max) { return RNG.next(Max); }
+  bool getTrueWithProbability(float Probability);
+  RandomNumberGeneratorWrapper(RandomNumberGenerator &RNG) : RNG(RNG) {}
+
+private:
+  RandomNumberGeneratorWrapper(const RandomNumberGeneratorWrapper &)
+      LLVM_DELETED_FUNCTION;
+  RandomNumberGeneratorWrapper &
+  operator=(const RandomNumberGeneratorWrapper &) LLVM_DELETED_FUNCTION;
+
+  RandomNumberGenerator &RNG;
+};
+
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICERNG_H