Subzero: Simplify the FakeKill instruction.

src/IceCfgNode.cpp

 //===- subzero/src/IceCfgNode.cpp - Basic block (node) 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 CfgNode class, including the complexities
@@ skipping 643 matching lines @@
   }
   // Process instructions
   for (auto I = Insts.begin(), E = Insts.end(); I != E; ++I) {
     I->deleteIfDead();
     if (I->isDeleted())
       continue;
     if (FirstInstNum == Inst::NumberSentinel)
       FirstInstNum = I->getNumber();
     assert(I->getNumber() > LastInstNum);
     LastInstNum = I->getNumber();
-    // Create fake live ranges for a Kill instruction, but only if the
-    // linked instruction is still alive.
-    if (Mode == Liveness_Intervals) {
-      if (InstFakeKill *Kill = llvm::dyn_cast<InstFakeKill>(I)) {
-        if (!Kill->getLinked()->isDeleted()) {
-          for (Variable *Var : Kill->getKilledRegs()) {
-            InstNumberT InstNumber = I->getNumber();
-            Var->addLiveRange(InstNumber, InstNumber, 1);
-          }
-        }
-      }
-    }
   }
   if (Mode != Liveness_Intervals)
     return;
   TimerMarker T1(TimerStack::TT_liveRangeCtor, Func);
 
   SizeT NumVars = Liveness->getNumVarsInNode(this);
   LivenessBV &LiveIn = Liveness->getLiveIn(this);
   LivenessBV &LiveOut = Liveness->getLiveOut(this);
   LiveBeginEndMap &MapBegin = *Liveness->getLiveBegin(this);
   LiveBeginEndMap &MapEnd = *Liveness->getLiveEnd(this);
@@ skipping 325 matching lines @@
       if (!First)
         Str << ", ";
       First = false;
       Str << "%" << I->getName();
     }
     Str << "\n";
   }
 }
 
 } // end of namespace Ice