Use separate random number generator for each randomization pass

src/IceCfg.cpp

 //===- subzero/src/IceCfg.cpp - Control flow graph implementation ---------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 25 matching lines @@
 
 Cfg::Cfg(GlobalContext *Ctx, uint32_t SequenceNumber)
     : Ctx(Ctx), SequenceNumber(SequenceNumber),
       VMask(Ctx->getFlags().getVerbose()), NextInstNumber(Inst::NumberInitial),
       Allocator(new ArenaAllocator<>()), Live(nullptr),
       Target(TargetLowering::createLowering(Ctx->getFlags().getTargetArch(),
                                             this)),
       VMetadata(new VariablesMetadata(this)),
       TargetAssembler(TargetLowering::createAssembler(
           Ctx->getFlags().getTargetArch(), this)) {
+  assert(!Ctx->isIRGenerationDisabled() &&
+         "Attempt to build cfg when IR generation disabled");
+  if (Ctx->getFlags().getRandomizeAndPoolImmediatesOption() == RPI_Randomize) {
+    // If -randomize-pool-immediates=randomize, create a random number generator
+    // to generate a cookie for constant blinding.
+    RandomNumberGenerator RNG(Ctx->getFlags().getRandomSeed(),
+                              RPE_ConstantBlinding, SequenceNumber);
+    ConstantBlindingCookie =
+        (uint32_t)RNG.next((uint64_t)std::numeric_limits<uint32_t>::max + 1);
+  }
 }
 
 Cfg::~Cfg() { assert(ICE_TLS_GET_FIELD(CurrentCfg) == nullptr); }
 
 void Cfg::setError(const IceString &Message) {
   HasError = true;
   ErrorMessage = Message;
 }
 
 CfgNode *Cfg::makeNode() {
@@ skipping 333 matching lines @@
 }
 } // end of anonymous namespace
 
 void Cfg::shuffleNodes() {
   if (!Ctx->getFlags().shouldReorderBasicBlocks())
     return;
 
   NodeList ReversedReachable;
   NodeList Unreachable;
   llvm::BitVector ToVisit(Nodes.size(), true);
+  // Create Random number generator for function reordering
+  RandomNumberGenerator RNG(Ctx->getFlags().getRandomSeed(),
+                            RPE_BasicBlockReordering, SequenceNumber);
   // Traverse from entry node.
-  getRandomPostOrder(getEntryNode(), ToVisit, ReversedReachable,
-                     &Ctx->getRNG());
+  getRandomPostOrder(getEntryNode(), ToVisit, ReversedReachable, &RNG);
   // Collect the unreachable nodes.
   for (CfgNode *Node : Nodes)
     if (ToVisit[Node->getIndex()])
       Unreachable.push_back(Node);
   // Copy the layout list to the Nodes.
   NodeList Shuffled;
   Shuffled.reserve(ReversedReachable.size() + Unreachable.size());
   for (CfgNode *Node : reverse_range(ReversedReachable))
     Shuffled.push_back(Node);
   for (CfgNode *Node : Unreachable)
@@ skipping 12 matching lines @@
 void Cfg::doAddressOpt() {
   TimerMarker T(TimerStack::TT_doAddressOpt, this);
   for (CfgNode *Node : Nodes)
     Node->doAddressOpt();
 }
 
 void Cfg::doNopInsertion() {
   if (!Ctx->getFlags().shouldDoNopInsertion())
     return;
   TimerMarker T(TimerStack::TT_doNopInsertion, this);
+  RandomNumberGenerator RNG(Ctx->getFlags().getRandomSeed(), RPE_NopInsertion,
+                            SequenceNumber);
   for (CfgNode *Node : Nodes)
-    Node->doNopInsertion();
+    Node->doNopInsertion(RNG);
 }
 
 void Cfg::genCode() {
   TimerMarker T(TimerStack::TT_genCode, this);
   for (CfgNode *Node : Nodes)
     Node->genCode();
 }
 
 // Compute the stack frame layout.
 void Cfg::genFrame() {
@@ skipping 313 matching lines @@
     }
   }
   // Print each basic block
   for (CfgNode *Node : Nodes)
     Node->dump(this);
   if (isVerbose(IceV_Instructions))
     Str << "}\n";
 }
 
 } // end of namespace Ice