Revert "Random Number Generator (llvm)"

This reverts commit cccba093090d127e0b6d17473b14c264c14c5259.

It causes build breakage.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211146 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/IR/Module.h

@@ -29,7 +29,6 @@ namespace llvm {
 class FunctionType;
 class GVMaterializer;
 class LLVMContext;
-class RandomNumberGenerator;
 class StructType;
 template<typename T> struct DenseMapInfo;
 template<typename KeyT, typename ValueT, typename KeyInfoT> class DenseMap;
@@ -202,8 +201,6 @@ private:
   std::string ModuleID;           ///< Human readable identifier for the module
   std::string TargetTriple;       ///< Platform target triple Module compiled on
   void *NamedMDSymTab;            ///< NamedMDNode names.
-  // Allow lazy initialization in const method.
-  mutable RandomNumberGenerator *RNG; ///< The random number generator for this module.
 
   // We need to keep the string because the C API expects us to own the string
   // representation.
@@ -252,11 +249,6 @@ public:
   /// @returns a string containing the module-scope inline assembly blocks.
   const std::string &getModuleInlineAsm() const { return GlobalScopeAsm; }
 
-  /// Get the RandomNumberGenerator for this module. The RNG can be
-  /// seeded via -rng-seed=<uint64> and is salted with the ModuleID.
-  /// The returned RNG should not be shared across threads.
-  RandomNumberGenerator &getRNG() const;
-
 /// @}
 /// @name Module Level Mutators
 /// @{

include/llvm/Support/RandomNumberGenerator.h

@@ -1,53 +0,0 @@
-//==- llvm/Support/RandomNumberGenerator.h - RNG for diversity ---*- 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 an abstraction for random number generation (RNG).
-// Note that the current implementation is not cryptographically secure
-// as it uses the C++11 <random> facilities.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_SUPPORT_RANDOMNUMBERGENERATOR_H_
-#define LLVM_SUPPORT_RANDOMNUMBERGENERATOR_H_
-
-#include "llvm/ADT/StringRef.h"
-#include <random>
-
-namespace llvm {
-
-/// A random number generator.
-/// Instances of this class should not be shared across threads.
-class RandomNumberGenerator {
-public:
-  /// Seeds and salts the underlying RNG engine. The salt of type StringRef
-  /// is passed into the constructor. The seed can be set on the command
-  /// line via -rng-seed=<uint64>.
-  /// The reason for the salt is to ensure different random streams even if
-  /// the same seed is used for multiple invocations of the compiler.
-  /// A good salt value should add additional entropy and be constant across
-  /// different machines (i.e., no paths) to allow for reproducible builds.
-  /// An instance of this class can be retrieved from the current Module.
-  /// \see Module::getRNG
-  RandomNumberGenerator(StringRef Salt);
-
-  /// Returns a random number in the range [0, Max).
-  uint64_t next(uint64_t Max);
-
-private:
-  // 64-bit Mersenne Twister by Matsumoto and Nishimura, 2000
-  // http://en.cppreference.com/w/cpp/numeric/random/mersenne_twister_engine
-  std::mt19937_64 Generator;
-
-  // Noncopyable.
-  RandomNumberGenerator(const RandomNumberGenerator &other) = delete;
-  RandomNumberGenerator &operator=(const RandomNumberGenerator &other) = delete;
-};
-}
-
-#endif

lib/IR/Module.cpp

@@ -24,8 +24,6 @@
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/LeakDetector.h"
 #include "llvm/Support/Dwarf.h"
-#include "llvm/Support/Path.h"
-#include "llvm/Support/RandomNumberGenerator.h"
 #include <algorithm>
 #include <cstdarg>
 #include <cstdlib>
@@ -46,7 +44,7 @@ template class llvm::SymbolTableListTraits<GlobalAlias, Module>;
 //
 
 Module::Module(StringRef MID, LLVMContext &C)
-    : Context(C), Materializer(), ModuleID(MID), RNG(nullptr), DL("") {
+    : Context(C), Materializer(), ModuleID(MID), DL("") {
   ValSymTab = new ValueSymbolTable();
   NamedMDSymTab = new StringMap<NamedMDNode *>();
   Context.addModule(this);
@@ -61,7 +59,6 @@ Module::~Module() {
   NamedMDList.clear();
   delete ValSymTab;
   delete static_cast<StringMap<NamedMDNode *> *>(NamedMDSymTab);
-  delete RNG;
 }
 
 /// getNamedValue - Return the first global value in the module with
@@ -358,16 +355,6 @@ const DataLayout *Module::getDataLayout() const {
   return &DL;
 }
 
-// We want reproducible builds, but ModuleID may be a full path so we just use
-// the filename to salt the RNG (although it is not guaranteed to be unique).
-RandomNumberGenerator &Module::getRNG() const {
-  if (RNG == nullptr) {
-    StringRef Salt = sys::path::filename(ModuleID);
-    RNG = new RandomNumberGenerator(Salt);
-  }
-  return *RNG;
-}
-
 //===----------------------------------------------------------------------===//
 // Methods to control the materialization of GlobalValues in the Module.
 //

lib/Support/CMakeLists.txt

@@ -41,7 +41,6 @@ add_llvm_library(LLVMSupport
   MD5.cpp
   PluginLoader.cpp
   PrettyStackTrace.cpp
-  RandomNumberGenerator.cpp
   Regex.cpp
   SmallPtrSet.cpp
   SmallVector.cpp

lib/Support/RandomNumberGenerator.cpp

@@ -1,52 +0,0 @@
-//===-- RandomNumberGenerator.cpp - Implement RNG class -------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements random number generation (RNG).
-// The current implementation is NOT cryptographically secure as it uses
-// the C++11 <random> facilities.
-//
-//===----------------------------------------------------------------------===//
-
-#define DEBUG_TYPE "rng"
-#include "llvm/Support/RandomNumberGenerator.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Debug.h"
-
-using namespace llvm;
-
-// Tracking BUG: 19665
-// http://llvm.org/bugs/show_bug.cgi?id=19665
-//
-// Do not change to cl::opt<uint64_t> since this silently breaks argument parsing.
-static cl::opt<unsigned long long>
-Seed("rng-seed", cl::value_desc("seed"),
-     cl::desc("Seed for the random number generator"), cl::init(0));
-
-RandomNumberGenerator::RandomNumberGenerator(StringRef Salt) {
-  DEBUG(
-    if (Seed == 0)
-      errs() << "Warning! Using unseeded random number generator.\n"
-  );
-
-  // Combine seed and salt using std::seed_seq.
-  // Entropy: Seed-low, Seed-high, Salt...
-  size_t Size = Salt.size() + 2;
-  uint32_t Data[Size];
-  Data[0] = Seed;
-  Data[1] = Seed >> 32;
-  std::copy_n(Salt.begin(), Salt.size(), Data + 2);
-
-  std::seed_seq SeedSeq(Data, Data + Size);
-  Generator.seed(SeedSeq);
-}
-
-uint64_t RandomNumberGenerator::next(uint64_t Max) {
-  std::uniform_int_distribution<uint64_t> distribution(0, Max - 1);
-  return distribution(Generator);
-}