Subzero: Improve debugging controls, plus minor refactoring.

src/IceLiveness.cpp

 //===- subzero/src/IceLiveness.cpp - Liveness analysis implementation -----===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file provides some of the support for the Liveness class.  In
@@ skipping 59 matching lines @@
       SizeT NodeIndex = VMetadata->getLocalUseNode(Var)->getIndex();
       LiveIndex = Nodes[NodeIndex].NumLocals++;
       Nodes[NodeIndex].LiveToVarMap[LiveIndex] = Var;
       LiveIndex += NumGlobals;
     }
     VarToLiveMap[VarIndex] = LiveIndex;
   }
   assert(NumGlobals == TmpNumGlobals);
 
   // Process each node.
-  const NodeList &LNodes = Func->getNodes();
-  SizeT NumLNodes = LNodes.size();
-  for (SizeT i = 0; i < NumLNodes; ++i) {
-    LivenessNode &Node = Nodes[LNodes[i]->getIndex()];
+  for (const CfgNode *LNode : Func->getNodes()) {
+    LivenessNode &Node = Nodes[LNode->getIndex()];
     // NumLocals, LiveToVarMap already initialized
     Node.LiveIn.resize(NumGlobals);
     Node.LiveOut.resize(NumGlobals);
     // LiveBegin and LiveEnd are reinitialized before each pass over
     // the block.
   }
 }
 
 Variable *Liveness::getVariable(SizeT LiveIndex, const CfgNode *Node) const {
   if (LiveIndex < NumGlobals)
     return LiveToVarMap[LiveIndex];
   SizeT NodeIndex = Node->getIndex();
   return Nodes[NodeIndex].LiveToVarMap[LiveIndex - NumGlobals];
 }
 
 } // end of namespace Ice