[C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206142 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/LiveIntervalAnalysis.cpp

@@ -79,7 +79,7 @@ void LiveIntervals::getAnalysisUsage(AnalysisUsage &AU) const {
 }
 
 LiveIntervals::LiveIntervals() : MachineFunctionPass(ID),
-  DomTree(0), LRCalc(0) {
+  DomTree(nullptr), LRCalc(nullptr) {
   initializeLiveIntervalsPass(*PassRegistry::getPassRegistry());
 }
 
@@ -572,9 +572,9 @@ void LiveIntervals::addKillFlags(const VirtRegMap *VRM) {
         break;
       }
       if (CancelKill)
-        MI->clearRegisterKills(Reg, NULL);
+        MI->clearRegisterKills(Reg, nullptr);
       else
-        MI->addRegisterKilled(Reg, NULL);
+        MI->addRegisterKilled(Reg, nullptr);
     }
   }
 }
@@ -590,17 +590,17 @@ LiveIntervals::intervalIsInOneMBB(const LiveInterval &LI) const {
 
   SlotIndex Start = LI.beginIndex();
   if (Start.isBlock())
-    return NULL;
+    return nullptr;
 
   SlotIndex Stop = LI.endIndex();
   if (Stop.isBlock())
-    return NULL;
+    return nullptr;
 
   // getMBBFromIndex doesn't need to search the MBB table when both indexes
   // belong to proper instructions.
   MachineBasicBlock *MBB1 = Indexes->getMBBFromIndex(Start);
   MachineBasicBlock *MBB2 = Indexes->getMBBFromIndex(Stop);
-  return MBB1 == MBB2 ? MBB1 : NULL;
+  return MBB1 == MBB2 ? MBB1 : nullptr;
 }
 
 bool