Answer to Philip Reames comments

[oota-llvm.git] / lib / Transforms / Scalar / LoopUnswitch.cpp

diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp
index 0becadceda7d79fefbec5c7d528979f574243208..977c53a3bc6327046fb53d31c9eaf8bddfef26b9 100644 (file)
--- a/lib/Transforms/Scalar/LoopUnswitch.cpp
+++ b/lib/Transforms/Scalar/LoopUnswitch.cpp
@@ -97,7 +97,7 @@ namespace {
     public:
 
       LUAnalysisCache() :
-        CurLoopInstructions(0), CurrentLoopProperties(0),
+        CurLoopInstructions(nullptr), CurrentLoopProperties(nullptr),
         MaxSize(Threshold)
       {}
 
@@ -152,8 +152,8 @@ namespace {
     static char ID; // Pass ID, replacement for typeid
     explicit LoopUnswitch(bool Os = false) :
       LoopPass(ID), OptimizeForSize(Os), redoLoop(false),
-      currentLoop(0), DT(0), loopHeader(0),
-      loopPreheader(0) {
+      currentLoop(nullptr), DT(nullptr), loopHeader(nullptr),
+      loopPreheader(nullptr) {
         initializeLoopUnswitchPass(*PassRegistry::getPassRegistry());
       }
 
@@ -204,8 +204,8 @@ namespace {
                                         Instruction *InsertPt);
 
     void SimplifyCode(std::vector<Instruction*> &Worklist, Loop *L);
-    bool IsTrivialUnswitchCondition(Value *Cond, Constant **Val = 0,
-                                    BasicBlock **LoopExit = 0);
+    bool IsTrivialUnswitchCondition(Value *Cond, Constant **Val = nullptr,
+                                    BasicBlock **LoopExit = nullptr);
 
   };
 }
@@ -274,8 +274,8 @@ void LUAnalysisCache::forgetLoop(const Loop *L) {
     LoopsProperties.erase(LIt);
   }
 
-  CurrentLoopProperties = 0;
-  CurLoopInstructions = 0;
+  CurrentLoopProperties = nullptr;
+  CurLoopInstructions = nullptr;
 }
 
 // Mark case value as unswitched.
@@ -346,10 +346,10 @@ static Value *FindLIVLoopCondition(Value *Cond, Loop *L, bool &Changed) {
 
   // We can never unswitch on vector conditions.
   if (Cond->getType()->isVectorTy())
-    return 0;
+    return nullptr;
 
   // Constants should be folded, not unswitched on!
-  if (isa<Constant>(Cond)) return 0;
+  if (isa<Constant>(Cond)) return nullptr;
 
   // TODO: Handle: br (VARIANT|INVARIANT).
 
@@ -369,7 +369,7 @@ static Value *FindLIVLoopCondition(Value *Cond, Loop *L, bool &Changed) {
         return RHS;
     }
 
-  return 0;
+  return nullptr;
 }
 
 bool LoopUnswitch::runOnLoop(Loop *L, LPPassManager &LPM_Ref) {
@@ -380,7 +380,7 @@ bool LoopUnswitch::runOnLoop(Loop *L, LPPassManager &LPM_Ref) {
   LPM = &LPM_Ref;
   DominatorTreeWrapperPass *DTWP =
       getAnalysisIfAvailable<DominatorTreeWrapperPass>();
-  DT = DTWP ? &DTWP->getDomTree() : 0;
+  DT = DTWP ? &DTWP->getDomTree() : nullptr;
   currentLoop = L;
   Function *F = currentLoop->getHeader()->getParent();
   bool Changed = false;
@@ -452,7 +452,7 @@ bool LoopUnswitch::processCurrentLoop() {
         // Find a value to unswitch on:
         // FIXME: this should chose the most expensive case!
         // FIXME: scan for a case with a non-critical edge?
-        Constant *UnswitchVal = 0;
+        Constant *UnswitchVal = nullptr;
 
         // Do not process same value again and again.
         // At this point we have some cases already unswitched and
@@ -509,7 +509,7 @@ static bool isTrivialLoopExitBlockHelper(Loop *L, BasicBlock *BB,
   if (!L->contains(BB)) {
     // Otherwise, this is a loop exit, this is fine so long as this is the
     // first exit.
-    if (ExitBB != 0) return false;
+    if (ExitBB) return false;
     ExitBB = BB;
     return true;
   }
@@ -536,10 +536,10 @@ static bool isTrivialLoopExitBlockHelper(Loop *L, BasicBlock *BB,
 static BasicBlock *isTrivialLoopExitBlock(Loop *L, BasicBlock *BB) {
   std::set<BasicBlock*> Visited;
   Visited.insert(L->getHeader());  // Branches to header make infinite loops.
-  BasicBlock *ExitBB = 0;
+  BasicBlock *ExitBB = nullptr;
   if (isTrivialLoopExitBlockHelper(L, BB, ExitBB, Visited))
     return ExitBB;
-  return 0;
+  return nullptr;
 }
 
 /// IsTrivialUnswitchCondition - Check to see if this unswitch condition is
@@ -560,7 +560,7 @@ bool LoopUnswitch::IsTrivialUnswitchCondition(Value *Cond, Constant **Val,
   TerminatorInst *HeaderTerm = Header->getTerminator();
   LLVMContext &Context = Header->getContext();
 
-  BasicBlock *LoopExitBB = 0;
+  BasicBlock *LoopExitBB = nullptr;
   if (BranchInst *BI = dyn_cast<BranchInst>(HeaderTerm)) {
     // If the header block doesn't end with a conditional branch on Cond, we
     // can't handle it.
@@ -630,8 +630,8 @@ bool LoopUnswitch::IsTrivialUnswitchCondition(Value *Cond, Constant **Val,
 /// unswitch the loop, reprocess the pieces, then return true.
 bool LoopUnswitch::UnswitchIfProfitable(Value *LoopCond, Constant *Val) {
   Function *F = loopHeader->getParent();
-  Constant *CondVal = 0;
-  BasicBlock *ExitBlock = 0;
+  Constant *CondVal = nullptr;
+  BasicBlock *ExitBlock = nullptr;
 
   if (IsTrivialUnswitchCondition(LoopCond, &CondVal, &ExitBlock)) {
     // If the condition is trivial, always unswitch. There is no code growth
@@ -1000,7 +1000,7 @@ void LoopUnswitch::RewriteLoopBodyWithConditionConstant(Loop *L, Value *LIC,
 
     // If we know that LIC is not Val, use this info to simplify code.
     SwitchInst *SI = dyn_cast<SwitchInst>(UI);
-    if (SI == 0 || !isa<ConstantInt>(Val)) continue;
+    if (!SI || !isa<ConstantInt>(Val)) continue;
 
     SwitchInst::CaseIt DeadCase = SI->findCaseValue(cast<ConstantInt>(Val));
     // Default case is live for multiple values.