Subzero: Add branch optimization.

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.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the Cfg class, including constant pool
@@ skipping 272 matching lines @@
             Var->dump(this);
             Str << " live range " << Var->getLiveRange() << "\n";
           }
         }
       }
     }
   }
   return Valid;
 }
 
+void Cfg::doBranchOpt() {
+  for (NodeList::iterator I = Nodes.begin(), E = Nodes.end(); I != E; ++I) {
+    NodeList::iterator NextNode = I;
+    ++NextNode;
+    (*I)->doBranchOpt(*NextNode);
+  }
+}
+
 // ======================== Dump routines ======================== //
 
 void Cfg::emit() {
   Ostream &Str = Ctx->getStrEmit();
   Timer T_emit;
   if (!Ctx->testAndSetHasEmittedFirstMethod()) {
     // Print a helpful command for assembling the output.
     // TODO: have the Target emit the header
     // TODO: need a per-file emit in addition to per-CFG
     Str << "# $LLVM_BIN_PATH/llvm-mc"
@@ skipping 72 matching lines @@
   for (NodeList::const_iterator I = Nodes.begin(), E = Nodes.end(); I != E;
        ++I) {
     (*I)->dump(this);
   }
   if (getContext()->isVerbose(IceV_Instructions)) {
     Str << "}\n";
   }
 }
 
 } // end of namespace Ice