[Transforms] Use {DenseMap,SmallPtrSet}::contains (NFC)

Author: kazutakahirata

llvm/lib/Transforms/Scalar/DFAJumpThreading.cpp

@@ -521,7 +521,7 @@ struct AllSwitchPaths {
 
       const BasicBlock *PrevBB = Path.back();
       for (const BasicBlock *BB : Path) {
-        if (StateDef.count(BB) != 0) {
+        if (StateDef.contains(BB)) {
           const PHINode *Phi = dyn_cast<PHINode>(StateDef[BB]);
           assert(Phi && "Expected a state-defining instr to be a phi node.");
 

llvm/lib/Transforms/Scalar/GVN.cpp

@@ -592,7 +592,7 @@ uint32_t GVNPass::ValueTable::lookupOrAddCall(CallInst *C) {
 
 /// Returns true if a value number exists for the specified value.
 bool GVNPass::ValueTable::exists(Value *V) const {
-  return valueNumbering.count(V) != 0;
+  return valueNumbering.contains(V);
 }
 
 /// lookup_or_add - Returns the value number for the specified value, assigning

llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp

@@ -2057,7 +2057,7 @@ static void relocationViaAlloca(
   for (const auto &Info : Records)
     for (auto RematerializedValuePair : Info.RematerializedValues) {
       Value *OriginalValue = RematerializedValuePair.second;
-      if (AllocaMap.count(OriginalValue) != 0)
+      if (AllocaMap.contains(OriginalValue))
         continue;
 
       emitAllocaFor(OriginalValue);

llvm/lib/Transforms/Utils/MemoryTaggingSupport.cpp

@@ -64,7 +64,7 @@ bool forAllReachableExits(const DominatorTree &DT, const PostDominatorTree &PDT,
     // sure that the return is covered. Otherwise, we can check whether there
     // is a way to reach the RI from the start of the lifetime without passing
     // through an end.
-    if (EndBlocks.count(RI->getParent()) > 0 ||
+    if (EndBlocks.contains(RI->getParent()) ||
         !isPotentiallyReachable(Start, RI, &EndBlocks, &DT, &LI)) {
       ++NumCoveredExits;
     }

llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

@@ -6443,7 +6443,7 @@ bool BoUpSLP::areAllUsersVectorized(
     Instruction *I, const SmallDenseSet<Value *> *VectorizedVals) const {
   return (I->hasOneUse() && (!VectorizedVals || VectorizedVals->contains(I))) ||
          all_of(I->users(), [this](User *U) {
-           return ScalarToTreeEntry.count(U) > 0 ||
+           return ScalarToTreeEntry.contains(U) ||
                   isVectorLikeInstWithConstOps(U) ||
                   (isa<ExtractElementInst>(U) && MustGather.contains(U));
          });