Use separate random number generator for each randomization pass

src/IceDefs.h

 //===- subzero/src/IceDefs.h - Common Subzero declarations ------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 257 matching lines @@
   return llvm::make_range(Container.rbegin(), Container.rend());
 }
 template <typename T>
 llvm::iterator_range<typename T::reverse_iterator> reverse_range(T &Container) {
   return llvm::make_range(Container.rbegin(), Container.rend());
 }
 
 /// Options for pooling and randomization of immediates.
 enum RandomizeAndPoolImmediatesEnum { RPI_None, RPI_Randomize, RPI_Pool };
 
+/// Salts for Random number generator for different randomization passes.
+enum RandomizationPassesEnum {
+  RS_BasicBlockReordering,

[Jim Stichnoth, 2015/08/19 19:03:04]

Usually the enum value prefix is directly derived from the enum type name, so
here it might be RPE_ .

[qining, 2015/08/19 23:25:48]

Done.

+  RS_ConstantBlinding,
+  RS_FunctionReordering,
+  RS_GlobalVariableReordering,
+  RS_NopInsertion,
+  RS_PooledConstantReordering,
+  RS_RegAllocRandomization,
+  RS_END = 16

[Jim Stichnoth, 2015/08/19 19:03:04]

Instead, use
  RPE_num

The _num name is used in lots of enums in the code base.

And there's no reason to specify 16 here.

[qining, 2015/08/19 23:25:48]

Done.

+};
+
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEDEFS_H