[LoopVectorize][NFCI] Use find instead of count

[xbolva00]

Summary

Avoid "count" if possible -> use "find" to check for the existence of keys.

Passed llvm test suite.

[fhahn]

LGTM thanks. Can you run clang-format on the diff before committing? Also adding a few more people as reviewers, please wait with committing a day or so in case there is any more feedback.

lib/Transforms/Vectorize/LoopVectorize.cpp

1276

nit: Could be one line?

[xbolva00]

• Formatted using clang-format

lib/Transforms/Vectorize/LoopVectorize.cpp

public:
   ///
   /// \returns false if the instruction doesn't belong to the group.
   bool insertMember(Instruction *Instr, int Index, unsigned NewAlign) {
     assert(NewAlign && "The new member's alignment should be non-zero");
 
     int Key = Index + SmallestKey;
 
     // Skip if there is already a member with the same index.
-    if (Members.count(Key))
+    if (Members.find(Key) != Members.end())
       return false;
 
     if (Key > LargestKey) {
       // The largest index is always less than the interleave factor.
       if (Index >= static_cast<int>(Factor))
         return false;
 
       LargestKey = Key;
bool insertMember(Instruction *Instr, int Index, unsigned NewAlign) {
     return true;
   }
 
   /// Get the member with the given index \p Index
   ///
   /// \returns nullptr if contains no such member.
   Instruction *getMember(unsigned Index) const {
     int Key = SmallestKey + Index;
-    if (!Members.count(Key))
+    auto Member = Members.find(Key);
+    if (Member == Members.end())
       return nullptr;
 
-    return Members.find(Key)->second;
+    return Member->second;
   }
 
   /// Get the index for the given member. Unlike the key in the member
   /// map, the index starts from 0.
   unsigned getIndex(Instruction *Instr) const {
     for (auto I : Members)
       if (I.second == Instr)
         return I.first - SmallestKey;
public:
   }
 
   /// Analyze the interleaved accesses and collect them in interleave
   /// groups. Substitute symbolic strides using \p Strides.
   void analyzeInterleaving();
 
   /// Check if \p Instr belongs to any interleave group.
   bool isInterleaved(Instruction *Instr) const {
-    return InterleaveGroupMap.count(Instr);
+    return InterleaveGroupMap.find(Instr) != InterleaveGroupMap.end();
   }
 
   /// Get the interleave group that \p Instr belongs to.
   ///
   /// \returns nullptr if doesn't have such group.
   InterleaveGroup *getInterleaveGroup(Instruction *Instr) const {
-    if (InterleaveGroupMap.count(Instr))
-      return InterleaveGroupMap.find(Instr)->second;
+    auto Group = InterleaveGroupMap.find(Instr);
+    if (Group == InterleaveGroupMap.end())
       return nullptr;
+    return Group->second;
   }
 
   /// Returns true if an interleaved group that may access memory
   /// out-of-bounds requires a scalar epilogue iteration for correctness.
   bool requiresScalarEpilogue() const { return RequiresScalarEpilogue; }
 
 private:
   /// A wrapper around ScalarEvolution, used to add runtime SCEV checks.
private:
   using StrideEntry = std::pair<Instruction *, StrideDescriptor>;
 
   /// Create a new interleave group with the given instruction \p Instr,
   /// stride \p Stride and alignment \p Align.
   ///
   /// \returns the newly created interleave group.
   InterleaveGroup *createInterleaveGroup(Instruction *Instr, int Stride,
                                          unsigned Align) {
-    assert(!InterleaveGroupMap.count(Instr) &&
+    assert(!isInterleaved(Instr) &&
            "Already in an interleaved access group");
     InterleaveGroupMap[Instr] = new InterleaveGroup(Instr, Stride, Align);
     return InterleaveGroupMap[Instr];
   }
 
   /// Release the group and remove all the relationships.
   void releaseGroup(InterleaveGroup *Group) {
     for (unsigned i = 0; i < Group->getFactor(); i++)
bool canReorderMemAccessesForInterleavedGroups(StrideEntry *A,
 
     // If dependence information is not available from LoopAccessInfo,
     // conservatively assume the instructions can't be reordered.
     if (!areDependencesValid())
       return false;
 
     // If we know there is a dependence from source to sink, assume the
     // instructions can't be reordered. Otherwise, reordering is legal.
-    return !Dependences.count(Src) || !Dependences.lookup(Src).count(Sink);
+    return Dependences.find(Src) == Dependences.end() || !Dependences.lookup(Src).count(Sink);
   }
 
   /// Collect the dependences from LoopAccessInfo.
   ///
   /// We process the dependences once during the interleaved access analysis to
   /// enable constant-time dependence queries.
   void collectDependences() {
     if (!areDependencesValid())
public:
 
   /// \returns True if it is more profitable to scalarize instruction \p I for
   /// vectorization factor \p VF.
   bool isProfitableToScalarize(Instruction *I, unsigned VF) const {
     assert(VF > 1 && "Profitable to scalarize relevant only for VF > 1.");
     auto Scalars = InstsToScalarize.find(VF);
     assert(Scalars != InstsToScalarize.end() &&
            "VF not yet analyzed for scalarization profitability");
-    return Scalars->second.count(I);
+    auto InstSet = Scalars->second;
+    return InstSet.find(I) != InstSet.end();
   }
 
   /// Returns true if \p I is known to be uniform after vectorization.
   bool isUniformAfterVectorization(Instruction *I, unsigned VF) const {
     if (VF == 1)
       return true;
-    assert(Uniforms.count(VF) && "VF not yet analyzed for uniformity");
     auto UniformsPerVF = Uniforms.find(VF);
-    return UniformsPerVF->second.count(I);
+    assert(UniformsPerVF != Uniforms.end() && "VF not yet analyzed for uniformity");
+    auto InstSet = UniformsPerVF->second;
+    return InstSet.find(I) != InstSet.end();
   }
 
   /// Returns true if \p I is known to be scalar after vectorization.
   bool isScalarAfterVectorization(Instruction *I, unsigned VF) const {
     if (VF == 1)
       return true;
-    assert(Scalars.count(VF) && "Scalar values are not calculated for VF");
     auto ScalarsPerVF = Scalars.find(VF);
-    return ScalarsPerVF->second.count(I);
+    assert(ScalarsPerVF != Scalars.end() && "Scalar values are not calculated for VF");
+    auto InstSet = ScalarsPerVF->second;
+    return InstSet.find(I) != InstSet.end();
   }
 
   /// \returns True if instruction \p I can be truncated to a smaller bitwidth
   /// for vectorization factor \p VF.
   bool canTruncateToMinimalBitwidth(Instruction *I, unsigned VF) const {
-    return VF > 1 && MinBWs.count(I) && !isProfitableToScalarize(I, VF) &&
+    return VF > 1 && MinBWs.find(I) != MinBWs.end() && !isProfitableToScalarize(I, VF) &&
            !isScalarAfterVectorization(I, VF);
   }
 
   /// Decision that was taken during cost calculation for memory instruction.
   enum InstWidening {
     CM_Unknown,
     CM_Widen,         // For consecutive accesses with stride +1.
     CM_Widen_Reverse, // For consecutive accesses with stride -1.
InstWidening getWideningDecision(Instruction *I, unsigned VF) {
     return Itr->second.first;
   }
 
   /// Return the vectorization cost for the given instruction \p I and vector
   /// width \p VF.
   unsigned getWideningCost(Instruction *I, unsigned VF) {
     assert(VF >= 2 && "Expected VF >=2");
     std::pair<Instruction *, unsigned> InstOnVF = std::make_pair(I, VF);
-    assert(WideningDecisions.count(InstOnVF) && "The cost is not calculated");
+    assert(WideningDecisions.find(InstOnVF) != WideningDecisions.end() && "The cost is not calculated");
     return WideningDecisions[InstOnVF].second;
   }
 
   /// Return True if instruction \p I is an optimizable truncate whose operand
   /// is an induction variable. Such a truncate will be removed by adding a new
   /// induction variable with the destination type.
   bool isOptimizableIVTruncate(Instruction *I, unsigned VF) {
     // If the instruction is not a truncate, return false.
public:
   /// the loop.
   void collectInstsToScalarize(unsigned VF);
 
   /// Collect Uniform and Scalar values for the given \p VF.
   /// The sets depend on CM decision for Load/Store instructions
   /// that may be vectorized as interleave, gather-scatter or scalarized.
   void collectUniformsAndScalars(unsigned VF) {
     // Do the analysis once.
-    if (VF == 1 || Uniforms.count(VF))
+    if (VF == 1 || Uniforms.find(VF) != Uniforms.end())
       return;
     setCostBasedWideningDecision(VF);
     collectLoopUniforms(VF);
     collectLoopScalars(VF);
   }
 
   /// Returns true if the target machine supports masked store operation
   /// for the given \p DataType and kind of access to \p Ptr.
void InnerLoopVectorizer::truncateToMinimalBitwidths() {
   for (const auto &KV : Cost->getMinimalBitwidths()) {
     // If the value wasn't vectorized, we must maintain the original scalar
     // type. The absence of the value from VectorLoopValueMap indicates that it
     // wasn't vectorized.
     if (!VectorLoopValueMap.hasAnyVectorValue(KV.first))
       continue;
     for (unsigned Part = 0; Part < UF; ++Part) {
       Value *I = getOrCreateVectorValue(KV.first, Part);
-      if (Erased.count(I) || I->use_empty() || !isa<Instruction>(I))
+      if (Erased.find(I) != Erased.end() || I->use_empty() || !isa<Instruction>(I))
         continue;
       Type *OriginalTy = I->getType();
       Type *ScalarTruncatedTy =
           IntegerType::get(OriginalTy->getContext(), KV.second);
       Type *TruncatedTy = VectorType::get(ScalarTruncatedTy,
                                           OriginalTy->getVectorNumElements());
       if (TruncatedTy == OriginalTy)
         continue;
void InnerLoopVectorizer::updateAnalysis() {
   DT->changeImmediateDominator(LoopExitBlock, LoopBypassBlocks[0]);
   assert(DT->verify(DominatorTree::VerificationLevel::Fast));
 }
 
 void LoopVectorizationCostModel::collectLoopScalars(unsigned VF) {
   // We should not collect Scalars more than once per VF. Right now, this
   // function is called from collectUniformsAndScalars(), which already does
   // this check. Collecting Scalars for VF=1 does not make any sense.
-  assert(VF >= 2 && !Scalars.count(VF) &&
+  assert(VF >= 2 && Scalars.find(VF) == Scalars.end() &&
          "This function should not be visited twice for the same VF");
 
   SmallSetVector<Instruction *, 8> Worklist;
 
   // These sets are used to seed the analysis with pointers used by memory
   // accesses that will remain scalar.
   SmallSetVector<Instruction *, 8> ScalarPtrs;
   SmallPtrSet<Instruction *, 8> PossibleNonScalarPtrs;
for (auto &I : *BB) {
       if (auto *Load = dyn_cast<LoadInst>(&I)) {
         evaluatePtrUse(Load, Load->getPointerOperand());
       } else if (auto *Store = dyn_cast<StoreInst>(&I)) {
         evaluatePtrUse(Store, Store->getPointerOperand());
         evaluatePtrUse(Store, Store->getValueOperand());
       }
     }
   for (auto *I : ScalarPtrs)
-    if (!PossibleNonScalarPtrs.count(I)) {
+    if (PossibleNonScalarPtrs.find(I) == PossibleNonScalarPtrs.end()) {
       LLVM_DEBUG(dbgs() << "LV: Found scalar instruction: " << *I << "\n");
       Worklist.insert(I);
     }
 
   // (3) Add to the worklist all pointer induction variables and their update
   // instructions.
   //
   // TODO: Once we are able to vectorize pointer induction variables we should
for (auto &Induction : *Legal->getInductionVars()) {
     LLVM_DEBUG(dbgs() << "LV: Found scalar instruction: " << *Ind << "\n");
     LLVM_DEBUG(dbgs() << "LV: Found scalar instruction: " << *IndUpdate
                       << "\n");
   }
 
   // Insert the forced scalars.
   // FIXME: Currently widenPHIInstruction() often creates a dead vector
   // induction variable when the PHI user is scalarized.
-  if (ForcedScalars.count(VF))
-    for (auto *I : ForcedScalars.find(VF)->second)
+  auto ForcedScalar = ForcedScalars.find(VF);
+  if (ForcedScalar != ForcedScalars.end())
+    for (auto *I : ForcedScalar->second)
       Worklist.insert(I);
 
   // Expand the worklist by looking through any bitcasts and getelementptr
   // instructions we've already identified as scalar. This is similar to the
   // expansion step in collectLoopUniforms(); however, here we're only
   // expanding to include additional bitcasts and getelementptr instructions.
   unsigned Idx = 0;
   while (Idx != Worklist.size()) {

 }
 
 void LoopVectorizationCostModel::collectLoopUniforms(unsigned VF) {
   // We should not collect Uniforms more than once per VF. Right now,
   // this function is called from collectUniformsAndScalars(), which
   // already does this check. Collecting Uniforms for VF=1 does not make any
   // sense.
 
-  assert(VF >= 2 && !Uniforms.count(VF) &&
+  assert(VF >= 2 && Uniforms.find(VF) == Uniforms.end() &&
          "This function should not be visited twice for the same VF");
 
   // Visit the list of Uniforms. If we'll not find any uniform value, we'll
   // not analyze again.  Uniforms.count(VF) will return 1.
   Uniforms[VF].clear();
 
   // We now know that the loop is vectorizable!
   // Collect instructions inside the loop that will remain uniform after
for (auto &I : *BB) {
       // remain uniform.
       else
         ConsecutiveLikePtrs.insert(Ptr);
     }
 
   // Add to the Worklist all consecutive and consecutive-like pointers that
   // aren't also identified as possibly non-uniform.
   for (auto *V : ConsecutiveLikePtrs)
-    if (!PossibleNonUniformPtrs.count(V)) {
+    if (PossibleNonUniformPtrs.find(V) == PossibleNonUniformPtrs.end()) {
       LLVM_DEBUG(dbgs() << "LV: Found uniform instruction: " << *V << "\n");
       Worklist.insert(V);
     }
 
   // Expand Worklist in topological order: whenever a new instruction
   // is added , its users should be already inside Worklist.  It ensures
   // a uniform instruction will only be used by uniform instructions.
   unsigned idx = 0;
LoopVectorizationCostModel::getSmallestAndWidestTypes() {
 
   // For each block.
   for (BasicBlock *BB : TheLoop->blocks()) {
     // For each instruction in the loop.
     for (Instruction &I : *BB) {
       Type *T = I.getType();
 
       // Skip ignored values.
-      if (ValuesToIgnore.count(&I))
+      if (ValuesToIgnore.find(&I) != ValuesToIgnore.end())
         continue;
 
       // Only examine Loads, Stores and PHINodes.
       if (!isa<LoadInst>(I) && !isa<StoreInst>(I) && !isa<PHINode>(I))
         continue;
 
       // Examine PHI nodes that are reduction variables. Update the type to
       // account for the recurrence type.
for (unsigned int i = 0; i < Index; ++i) {
     Instruction *I = IdxToInstr[i];
 
     // Remove all of the instructions that end at this location.
     InstrList &List = TransposeEnds[i];
     for (Instruction *ToRemove : List)
       OpenIntervals.erase(ToRemove);
 
     // Ignore instructions that are never used within the loop.
-    if (!Ends.count(I))
+    if (Ends.find(I) == Ends.end())
       continue;
 
     // Skip ignored values.
-    if (ValuesToIgnore.count(I))
+    if (ValuesToIgnore.find(I) != ValuesToIgnore.end())
       continue;
 
     // For each VF find the maximum usage of registers.
     for (unsigned j = 0, e = VFs.size(); j < e; ++j) {
       if (VFs[j] == 1) {
         MaxUsages[j] = std::max(MaxUsages[j], OpenIntervals.size());
         continue;
       }
       collectUniformsAndScalars(VFs[j]);
       // Count the number of live intervals.
       unsigned RegUsage = 0;
       for (auto Inst : OpenIntervals) {
         // Skip ignored values for VF > 1.
-        if (VecValuesToIgnore.count(Inst) ||
+        if (VecValuesToIgnore.find(Inst) != VecValuesToIgnore.end() ||
             isScalarAfterVectorization(Inst, VFs[j]))
           continue;
         RegUsage += GetRegUsage(Inst->getType(), VFs[j]);
       }
       MaxUsages[j] = std::max(MaxUsages[j], RegUsage);
     }
 
     LLVM_DEBUG(dbgs() << "LV(REG): At #" << i << " Interval # "
return isa<LoadInst>(I) ||
           NumPredStores > NumberOfStoresToPredicate);
 }
 
 void LoopVectorizationCostModel::collectInstsToScalarize(unsigned VF) {
   // If we aren't vectorizing the loop, or if we've already collected the
   // instructions to scalarize, there's nothing to do. Collection may already
   // have occurred if we have a user-selected VF and are now computing the
   // expected cost for interleaving.
-  if (VF < 2 || InstsToScalarize.count(VF))
+  if (VF < 2 || InstsToScalarize.find(VF) != InstsToScalarize.end())
     return;
 
   // Initialize a mapping for VF in InstsToScalalarize. If we find that it's
   // not profitable to scalarize any instructions, the presence of VF in the
   // map will indicate that we've analyzed it already.
   ScalarCostsTy &ScalarCostsVF = InstsToScalarize[VF];
 
   // Find all the instructions that are scalar with predication in the loop and
int LoopVectorizationCostModel::computePredInstDiscount(
   // Compute the expected cost discount from scalarizing the entire expression
   // feeding the predicated instruction. We currently only consider expressions
   // that are single-use instruction chains.
   Worklist.push_back(PredInst);
   while (!Worklist.empty()) {
     Instruction *I = Worklist.pop_back_val();
 
     // If we've already analyzed the instruction, there's nothing to do.
-    if (ScalarCosts.count(I))
+    if (ScalarCosts.find(I) != ScalarCosts.end())
       continue;
 
     // Compute the cost of the vector instruction. Note that this cost already
     // includes the scalarization overhead of the predicated instruction.
     unsigned VectorCost = getInstructionCost(I, VF).first;
 
     // Compute the cost of the scalarized instruction. This cost is the cost of
     // the instruction as if it wasn't if-converted and instead remained in the
LoopVectorizationCostModel::expectedCost(unsigned VF) {
 
   // For each block.
   for (BasicBlock *BB : TheLoop->blocks()) {
     VectorizationCostTy BlockCost;
 
     // For each instruction in the old loop.
     for (Instruction &I : BB->instructionsWithoutDebug()) {
       // Skip ignored values.
-      if (ValuesToIgnore.count(&I) ||
-          (VF > 1 && VecValuesToIgnore.count(&I)))
+      if (ValuesToIgnore.find(&I) != ValuesToIgnore.end() ||
+          (VF > 1 && VecValuesToIgnore.find(&I) != VecValuesToIgnore.end()))
         continue;
 
       VectorizationCostTy C = getInstructionCost(&I, VF);
 
       // Check if we should override the cost.
       if (ForceTargetInstructionCost.getNumOccurrences() > 0)
         C.first = ForceTargetInstructionCost;
 
LoopVectorizationCostModel::getInstructionCost(Instruction *I, unsigned VF) {
   // the scalar version.
   if (isUniformAfterVectorization(I, VF))
     VF = 1;
 
   if (VF > 1 && isProfitableToScalarize(I, VF))
     return VectorizationCostTy(InstsToScalarize[VF][I], false);
 
   // Forced scalars do not have any scalarization overhead.
-  if (VF > 1 && ForcedScalars.count(VF) &&
-      ForcedScalars.find(VF)->second.count(I))
+  auto ForcedScalar = ForcedScalars.find(VF);
+  if (VF > 1 && ForcedScalar != ForcedScalars.end()) {
+    auto InstSet = ForcedScalar->second;
+    if (InstSet.find(I) != InstSet.end())
       return VectorizationCostTy((getInstructionCost(I, 1).first * VF), false);
+  }
 
   Type *VectorTy;
   unsigned C = getInstructionCost(I, VF, VectorTy);
 
   bool TypeNotScalarized =
       VF > 1 && VectorTy->isVectorTy() && TTI.getNumberOfParts(VectorTy) < VF;
   return VectorizationCostTy(C, TypeNotScalarized);
 }
case Instruction::GetElementPtr:
     return 0;
   case Instruction::Br: {
     // In cases of scalarized and predicated instructions, there will be VF
     // predicated blocks in the vectorized loop. Each branch around these
     // blocks requires also an extract of its vector compare i1 element.
     bool ScalarPredicatedBB = false;
     BranchInst *BI = cast<BranchInst>(I);
     if (VF > 1 && BI->isConditional() &&
-        (PredicatedBBsAfterVectorization.count(BI->getSuccessor(0)) ||
-         PredicatedBBsAfterVectorization.count(BI->getSuccessor(1))))
+        (PredicatedBBsAfterVectorization.find(BI->getSuccessor(0)) != PredicatedBBsAfterVectorization.end() ||
+         PredicatedBBsAfterVectorization.find(BI->getSuccessor(1)) != PredicatedBBsAfterVectorization.end()))
       ScalarPredicatedBB = true;
 
     if (ScalarPredicatedBB) {
       // Return cost for branches around scalarized and predicated blocks.
       Type *Vec_i1Ty =
           VectorType::get(IntegerType::getInt1Ty(RetTy->getContext()), VF);
       return (TTI.getScalarizationOverhead(Vec_i1Ty, false, true) +
               (TTI.getCFInstrCost(Instruction::Br) * VF));
void LoopVectorizationPlanner::collectTriviallyDeadInstructions(
 
   // We create new "steps" for induction variable updates to which the original
   // induction variables map. An original update instruction will be dead if
   // all its users except the induction variable are dead.
   for (auto &Induction : *Legal->getInductionVars()) {
     PHINode *Ind = Induction.first;
     auto *IndUpdate = cast<Instruction>(Ind->getIncomingValueForBlock(Latch));
     if (llvm::all_of(IndUpdate->users(), [&](User *U) -> bool {
-          return U == Ind || DeadInstructions.count(cast<Instruction>(U));
+          return U == Ind || DeadInstructions.find(cast<Instruction>(U)) != DeadInstructions.end();
         }))
       DeadInstructions.insert(IndUpdate);
 
     // We record as "Dead" also the type-casting instructions we had identified
     // during induction analysis. We don't need any handling for them in the
     // vectorized loop because we have proven that, under a proper runtime
     // test guarding the vectorized loop, the value of the phi, and the casted
     // value of the phi, are the same. The last instruction in this casting chain
for (BasicBlock *BB : make_range(DFS.beginRPO(), DFS.endRPO())) {
 
     // Organize the ingredients to vectorize from current basic block in the
     // right order.
     for (Instruction &I : BB->instructionsWithoutDebug()) {
       Instruction *Instr = &I;
 
       // First filter out irrelevant instructions, to ensure no recipes are
       // built for them.
-      if (isa<BranchInst>(Instr) || DeadInstructions.count(Instr))
+      if (isa<BranchInst>(Instr) || DeadInstructions.find(Instr) != DeadInstructions.end())
         continue;
 
       // I is a member of an InterleaveGroup for Range.Start. If it's an adjunct
       // member of the IG, do not construct any Recipe for it.
       const InterleaveGroup *IG = CM.getInterleavedAccessGroup(Instr);
       if (IG && Instr != IG->getInsertPos() &&
           Range.Start >= 2 && // Query is illegal for VF == 1
           CM.getWideningDecision(Instr, Range.Start) ==
               LoopVectorizationCostModel::CM_Interleave) {
-        if (SinkAfterInverse.count(Instr))
-          Ingredients.push_back(SinkAfterInverse.find(Instr)->second);
+        auto SinkCandidate = SinkAfterInverse.find(Instr);
+        if (SinkCandidate != SinkAfterInverse.end())
+          Ingredients.push_back(SinkCandidate->second);
         continue;
       }
 
       // Move instructions to handle first-order recurrences, step 1: avoid
       // handling this instruction until after we've handled the instruction it
       // should follow.
       auto SAIt = SinkAfter.find(Instr);
       if (SAIt != SinkAfter.end()) {