Compute the loop nest depth of each CfgNode and weight Variables by it.

src/IceInst.cpp

 //===- subzero/src/IceInst.cpp - High-level instruction implementation ----===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 414 matching lines @@
 }
 
 InstStore::InstStore(Cfg *Func, Operand *Data, Operand *Addr)
     : InstHighLevel(Func, Inst::Store, 3, nullptr) {
   addSource(Data);
   addSource(Addr);
   // The 3rd operand is a dummy placeholder for the RMW beacon.
   addSource(Data);
 }
 
+Variable *InstStore::getRmwBeacon() const {
+  return llvm::dyn_cast<Variable>(getSrc(2));
+}
+
 void InstStore::setRmwBeacon(Variable *Beacon) {
   Dest = llvm::dyn_cast<Variable>(getData());
   Srcs[2] = Beacon;
 }
 
 InstSwitch::InstSwitch(Cfg *Func, SizeT NumCases, Operand *Source,
                        CfgNode *LabelDefault)
     : InstHighLevel(Func, Inst::Switch, 1, nullptr), LabelDefault(LabelDefault),
       NumCases(NumCases) {
   addSource(Source);
@@ skipping 529 matching lines @@
     // preserve these.
     return true;
   }
   if (!Dest->hasReg() && !SrcVar->hasReg() &&
       Dest->getStackOffset() == SrcVar->getStackOffset())
     return true;
   return false;
 }
 
 } // end of namespace Ice