From: Tyler Nowicki <tyler.nowicki@gmail.com>
Date: Tue, 16 Jun 2015 18:07:34 +0000 (+0000)
Subject: Rename Reduction variables/structures to Recurrence.
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0a91310c7ffad8b597c1996fde68e5f0b6d27ad3;p=platform%2Fupstream%2Fllvm.git

Rename Reduction variables/structures to Recurrence.

A reduction is a special kind of recurrence. In the loop vectorizer we currently
identify basic reductions. Future patches will extend this to identifying basic
recurrences.

llvm-svn: 239835
---

diff --git a/llvm/include/llvm/Transforms/Utils/LoopUtils.h b/llvm/include/llvm/Transforms/Utils/LoopUtils.h
index 28791f5..3936f1d 100644
--- a/llvm/include/llvm/Transforms/Utils/LoopUtils.h
+++ b/llvm/include/llvm/Transforms/Utils/LoopUtils.h
@@ -43,12 +43,23 @@ struct LICMSafetyInfo {
   {}
 };
 
-/// This POD struct holds information about a potential reduction operation.
-class ReductionInstDesc {
+/// The RecurrenceDescriptor is used to identify recurrences variables in a
+/// loop. Reduction is a special case of recurrence that has uses of the
+/// recurrence variable outside the loop. The method isReductionPHI identifies
+/// reductions that are basic recurrences.
+///
+/// Basic recurrences are defined as the summation, product, OR, AND, XOR, min,
+/// or max of a set of terms. For example: for(i=0; i<n; i++) { total +=
+/// array[i]; } is a summation of array elements. Basic recurrences are a
+/// special case of chains of recurrences (CR). See ScalarEvolution for CR
+/// references.
+
+/// This POD struct holds information about a potential recurrence operation.
+class RecurrenceInstDesc {
 
 public:
-  // This enum represents the kind of minmax reduction.
-  enum MinMaxReductionKind {
+  // This enum represents the kind of minmax recurrence.
+  enum MinMaxRecurrenceKind {
     MRK_Invalid,
     MRK_UIntMin,
     MRK_UIntMax,
@@ -57,35 +68,35 @@ public:
     MRK_FloatMin,
     MRK_FloatMax
   };
-  ReductionInstDesc(bool IsRedux, Instruction *I)
-      : IsReduction(IsRedux), PatternLastInst(I), MinMaxKind(MRK_Invalid) {}
+  RecurrenceInstDesc(bool IsRecur, Instruction *I)
+      : IsRecurrence(IsRecur), PatternLastInst(I), MinMaxKind(MRK_Invalid) {}
+
+  RecurrenceInstDesc(Instruction *I, MinMaxRecurrenceKind K)
+      : IsRecurrence(true), PatternLastInst(I), MinMaxKind(K) {}
 
-  ReductionInstDesc(Instruction *I, MinMaxReductionKind K)
-      : IsReduction(true), PatternLastInst(I), MinMaxKind(K) {}
+  bool isRecurrence() { return IsRecurrence; }
 
-  bool isReduction() { return IsReduction; }
+  MinMaxRecurrenceKind getMinMaxKind() { return MinMaxKind; }
 
-  MinMaxReductionKind getMinMaxKind() { return MinMaxKind; }
- 
   Instruction *getPatternInst() { return PatternLastInst; }
 
 private:
-  // Is this instruction a reduction candidate.
-  bool IsReduction;
+  // Is this instruction a recurrence candidate.
+  bool IsRecurrence;
   // The last instruction in a min/max pattern (select of the select(icmp())
-  // pattern), or the current reduction instruction otherwise.
+  // pattern), or the current recurrence instruction otherwise.
   Instruction *PatternLastInst;
   // If this is a min/max pattern the comparison predicate.
-  MinMaxReductionKind MinMaxKind;
+  MinMaxRecurrenceKind MinMaxKind;
 };
 
-/// This struct holds information about reduction variables.
-class ReductionDescriptor {
+/// This struct holds information about recurrence variables.
+class RecurrenceDescriptor {
 
 public:
-  /// This enum represents the kinds of reductions that we support.
-  enum ReductionKind {
-    RK_NoReduction,   ///< Not a reduction.
+  /// This enum represents the kinds of recurrences that we support.
+  enum RecurrenceKind {
+    RK_NoRecurrence,  ///< Not a recurrence.
     RK_IntegerAdd,    ///< Sum of integers.
     RK_IntegerMult,   ///< Product of integers.
     RK_IntegerOr,     ///< Bitwise or logical OR of numbers.
@@ -97,22 +108,23 @@ public:
     RK_FloatMinMax    ///< Min/max implemented in terms of select(cmp()).
   };
 
-  ReductionDescriptor()
-      : StartValue(nullptr), LoopExitInstr(nullptr), Kind(RK_NoReduction),
-        MinMaxKind(ReductionInstDesc::MRK_Invalid) {}
+  RecurrenceDescriptor()
+      : StartValue(nullptr), LoopExitInstr(nullptr), Kind(RK_NoRecurrence),
+        MinMaxKind(RecurrenceInstDesc::MRK_Invalid) {}
 
-  ReductionDescriptor(Value *Start, Instruction *Exit, ReductionKind K,
-                      ReductionInstDesc::MinMaxReductionKind MK)
+  RecurrenceDescriptor(Value *Start, Instruction *Exit, RecurrenceKind K,
+                       RecurrenceInstDesc::MinMaxRecurrenceKind MK)
       : StartValue(Start), LoopExitInstr(Exit), Kind(K), MinMaxKind(MK) {}
 
-  /// Returns a struct describing if the instruction 'I' can be a reduction
-  /// variable of type 'Kind'. If the reduction is a min/max pattern of
+  /// Returns a struct describing if the instruction 'I' can be a recurrence
+  /// variable of type 'Kind'. If the recurrence is a min/max pattern of
   /// select(icmp()) this function advances the instruction pointer 'I' from the
   /// compare instruction to the select instruction and stores this pointer in
   /// 'PatternLastInst' member of the returned struct.
-  static ReductionInstDesc isReductionInstr(Instruction *I, ReductionKind Kind,
-                                            ReductionInstDesc &Prev,
-                                            bool HasFunNoNaNAttr);
+  static RecurrenceInstDesc isRecurrenceInstr(Instruction *I,
+                                              RecurrenceKind Kind,
+                                              RecurrenceInstDesc &Prev,
+                                              bool HasFunNoNaNAttr);
 
   /// Returns true if instuction I has multiple uses in Insts
   static bool hasMultipleUsesOf(Instruction *I,
@@ -124,51 +136,52 @@ public:
   /// Returns a struct describing if the instruction if the instruction is a
   /// Select(ICmp(X, Y), X, Y) instruction pattern corresponding to a min(X, Y)
   /// or max(X, Y).
-  static ReductionInstDesc isMinMaxSelectCmpPattern(Instruction *I,
-                                                    ReductionInstDesc &Prev);
+  static RecurrenceInstDesc isMinMaxSelectCmpPattern(Instruction *I,
+                                                     RecurrenceInstDesc &Prev);
 
-  /// Returns identity corresponding to the ReductionKind.
-  static Constant *getReductionIdentity(ReductionKind K, Type *Tp);
+  /// Returns identity corresponding to the RecurrenceKind.
+  static Constant *getRecurrenceIdentity(RecurrenceKind K, Type *Tp);
 
-  /// Returns the opcode of binary operation corresponding to the ReductionKind.
-  static unsigned getReductionBinOp(ReductionKind Kind);
+  /// Returns the opcode of binary operation corresponding to the
+  /// RecurrenceKind.
+  static unsigned getRecurrenceBinOp(RecurrenceKind Kind);
 
-  /// Returns a Min/Max operation corresponding to MinMaxReductionKind.
+  /// Returns a Min/Max operation corresponding to MinMaxRecurrenceKind.
   static Value *createMinMaxOp(IRBuilder<> &Builder,
-                               ReductionInstDesc::MinMaxReductionKind RK,
+                               RecurrenceInstDesc::MinMaxRecurrenceKind RK,
                                Value *Left, Value *Right);
 
   /// Returns true if Phi is a reduction of type Kind and adds it to the
-  /// ReductionDescriptor.
-  static bool AddReductionVar(PHINode *Phi, ReductionKind Kind, Loop *TheLoop,
+  /// RecurrenceDescriptor.
+  static bool AddReductionVar(PHINode *Phi, RecurrenceKind Kind, Loop *TheLoop,
                               bool HasFunNoNaNAttr,
-                              ReductionDescriptor &RedDes);
+                              RecurrenceDescriptor &RedDes);
 
-  /// Returns true if Phi is a reduction in TheLoop. The ReductionDescriptor is
+  /// Returns true if Phi is a reduction in TheLoop. The RecurrenceDescriptor is
   /// returned in RedDes.
   static bool isReductionPHI(PHINode *Phi, Loop *TheLoop,
-                             ReductionDescriptor &RedDes);
+                             RecurrenceDescriptor &RedDes);
 
-  ReductionKind getReductionKind() { return Kind; }
+  RecurrenceKind getRecurrenceKind() { return Kind; }
 
-  ReductionInstDesc::MinMaxReductionKind getMinMaxReductionKind() {
+  RecurrenceInstDesc::MinMaxRecurrenceKind getMinMaxRecurrenceKind() {
     return MinMaxKind;
   }
 
-  TrackingVH<Value> getReductionStartValue() { return StartValue; }
+  TrackingVH<Value> getRecurrenceStartValue() { return StartValue; }
 
   Instruction *getLoopExitInstr() { return LoopExitInstr; }
 
 private:
-  // The starting value of the reduction.
+  // The starting value of the recurrence.
   // It does not have to be zero!
   TrackingVH<Value> StartValue;
   // The instruction who's value is used outside the loop.
   Instruction *LoopExitInstr;
-  // The kind of the reduction.
-  ReductionKind Kind;
-  // If this a min/max reduction the kind of reduction.
-  ReductionInstDesc::MinMaxReductionKind MinMaxKind;
+  // The kind of the recurrence.
+  RecurrenceKind Kind;
+  // If this a min/max recurrence the kind of recurrence.
+  RecurrenceInstDesc::MinMaxRecurrenceKind MinMaxKind;
 };
 
 BasicBlock *InsertPreheaderForLoop(Loop *L, Pass *P);
diff --git a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
index f584018..2554655 100644
--- a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
@@ -598,8 +598,8 @@ struct LoopInterchange : public FunctionPass {
 bool LoopInterchangeLegality::areAllUsesReductions(Instruction *Ins, Loop *L) {
   return !std::any_of(Ins->user_begin(), Ins->user_end(), [=](User *U) -> bool {
     PHINode *UserIns = dyn_cast<PHINode>(U);
-    ReductionDescriptor RD;
-    return !UserIns || !ReductionDescriptor::isReductionPHI(UserIns, L, RD);
+    RecurrenceDescriptor RD;
+    return !UserIns || !RecurrenceDescriptor::isReductionPHI(UserIns, L, RD);
   });
 }
 
@@ -697,12 +697,12 @@ bool LoopInterchangeLegality::findInductionAndReductions(
   if (!L->getLoopLatch() || !L->getLoopPredecessor())
     return false;
   for (BasicBlock::iterator I = L->getHeader()->begin(); isa<PHINode>(I); ++I) {
-    ReductionDescriptor RD;
+    RecurrenceDescriptor RD;
     PHINode *PHI = cast<PHINode>(I);
     ConstantInt *StepValue = nullptr;
     if (isInductionPHI(PHI, SE, StepValue))
       Inductions.push_back(PHI);
-    else if (ReductionDescriptor::isReductionPHI(PHI, L, RD))
+    else if (RecurrenceDescriptor::isReductionPHI(PHI, L, RD))
       Reductions.push_back(PHI);
     else {
       DEBUG(
diff --git a/llvm/lib/Transforms/Utils/LoopUtils.cpp b/llvm/lib/Transforms/Utils/LoopUtils.cpp
index 5f25e6b..c37ecfc 100644
--- a/llvm/lib/Transforms/Utils/LoopUtils.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUtils.cpp
@@ -26,17 +26,17 @@ using namespace llvm::PatternMatch;
 
 #define DEBUG_TYPE "loop-utils"
 
-bool ReductionDescriptor::areAllUsesIn(Instruction *I,
-                                       SmallPtrSetImpl<Instruction *> &Set) {
+bool RecurrenceDescriptor::areAllUsesIn(Instruction *I,
+                                        SmallPtrSetImpl<Instruction *> &Set) {
   for (User::op_iterator Use = I->op_begin(), E = I->op_end(); Use != E; ++Use)
     if (!Set.count(dyn_cast<Instruction>(*Use)))
       return false;
   return true;
 }
 
-bool ReductionDescriptor::AddReductionVar(PHINode *Phi, ReductionKind Kind,
-                                          Loop *TheLoop, bool HasFunNoNaNAttr,
-                                          ReductionDescriptor &RedDes) {
+bool RecurrenceDescriptor::AddReductionVar(PHINode *Phi, RecurrenceKind Kind,
+                                           Loop *TheLoop, bool HasFunNoNaNAttr,
+                                           RecurrenceDescriptor &RedDes) {
   if (Phi->getNumIncomingValues() != 2)
     return false;
 
@@ -66,7 +66,7 @@ bool ReductionDescriptor::AddReductionVar(PHINode *Phi, ReductionKind Kind,
   // the number of instruction we saw from the recognized min/max pattern,
   //  to make sure we only see exactly the two instructions.
   unsigned NumCmpSelectPatternInst = 0;
-  ReductionInstDesc ReduxDesc(false, nullptr);
+  RecurrenceInstDesc ReduxDesc(false, nullptr);
 
   SmallPtrSet<Instruction *, 8> VisitedInsts;
   SmallVector<Instruction *, 8> Worklist;
@@ -111,8 +111,8 @@ bool ReductionDescriptor::AddReductionVar(PHINode *Phi, ReductionKind Kind,
       return false;
 
     // Any reduction instruction must be of one of the allowed kinds.
-    ReduxDesc = isReductionInstr(Cur, Kind, ReduxDesc, HasFunNoNaNAttr);
-    if (!ReduxDesc.isReduction())
+    ReduxDesc = isRecurrenceInstr(Cur, Kind, ReduxDesc, HasFunNoNaNAttr);
+    if (!ReduxDesc.isRecurrence())
       return false;
 
     // A reduction operation must only have one use of the reduction value.
@@ -164,7 +164,7 @@ bool ReductionDescriptor::AddReductionVar(PHINode *Phi, ReductionKind Kind,
       // Process instructions only once (termination). Each reduction cycle
       // value must only be used once, except by phi nodes and min/max
       // reductions which are represented as a cmp followed by a select.
-      ReductionInstDesc IgnoredVal(false, nullptr);
+      RecurrenceInstDesc IgnoredVal(false, nullptr);
       if (VisitedInsts.insert(UI).second) {
         if (isa<PHINode>(UI))
           PHIs.push_back(UI);
@@ -173,7 +173,7 @@ bool ReductionDescriptor::AddReductionVar(PHINode *Phi, ReductionKind Kind,
       } else if (!isa<PHINode>(UI) &&
                  ((!isa<FCmpInst>(UI) && !isa<ICmpInst>(UI) &&
                    !isa<SelectInst>(UI)) ||
-                  !isMinMaxSelectCmpPattern(UI, IgnoredVal).isReduction()))
+                  !isMinMaxSelectCmpPattern(UI, IgnoredVal).isRecurrence()))
         return false;
 
       // Remember that we completed the cycle.
@@ -197,11 +197,11 @@ bool ReductionDescriptor::AddReductionVar(PHINode *Phi, ReductionKind Kind,
   // only have a single instruction with out-of-loop users.
 
   // The ExitInstruction(Instruction which is allowed to have out-of-loop users)
-  // is saved as part of the ReductionDescriptor.
+  // is saved as part of the RecurrenceDescriptor.
 
   // Save the description of this reduction variable.
-  ReductionDescriptor RD(RdxStart, ExitInstruction, Kind,
-                         ReduxDesc.getMinMaxKind());
+  RecurrenceDescriptor RD(RdxStart, ExitInstruction, Kind,
+                          ReduxDesc.getMinMaxKind());
 
   RedDes = RD;
 
@@ -210,9 +210,9 @@ bool ReductionDescriptor::AddReductionVar(PHINode *Phi, ReductionKind Kind,
 
 /// Returns true if the instruction is a Select(ICmp(X, Y), X, Y) instruction
 /// pattern corresponding to a min(X, Y) or max(X, Y).
-ReductionInstDesc
-ReductionDescriptor::isMinMaxSelectCmpPattern(Instruction *I,
-                                              ReductionInstDesc &Prev) {
+RecurrenceInstDesc
+RecurrenceDescriptor::isMinMaxSelectCmpPattern(Instruction *I,
+                                               RecurrenceInstDesc &Prev) {
 
   assert((isa<ICmpInst>(I) || isa<FCmpInst>(I) || isa<SelectInst>(I)) &&
          "Expect a select instruction");
@@ -223,84 +223,84 @@ ReductionDescriptor::isMinMaxSelectCmpPattern(Instruction *I,
   // select.
   if ((Cmp = dyn_cast<ICmpInst>(I)) || (Cmp = dyn_cast<FCmpInst>(I))) {
     if (!Cmp->hasOneUse() || !(Select = dyn_cast<SelectInst>(*I->user_begin())))
-      return ReductionInstDesc(false, I);
-    return ReductionInstDesc(Select, Prev.getMinMaxKind());
+      return RecurrenceInstDesc(false, I);
+    return RecurrenceInstDesc(Select, Prev.getMinMaxKind());
   }
 
   // Only handle single use cases for now.
   if (!(Select = dyn_cast<SelectInst>(I)))
-    return ReductionInstDesc(false, I);
+    return RecurrenceInstDesc(false, I);
   if (!(Cmp = dyn_cast<ICmpInst>(I->getOperand(0))) &&
       !(Cmp = dyn_cast<FCmpInst>(I->getOperand(0))))
-    return ReductionInstDesc(false, I);
+    return RecurrenceInstDesc(false, I);
   if (!Cmp->hasOneUse())
-    return ReductionInstDesc(false, I);
+    return RecurrenceInstDesc(false, I);
 
   Value *CmpLeft;
   Value *CmpRight;
 
   // Look for a min/max pattern.
   if (m_UMin(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
-    return ReductionInstDesc(Select, ReductionInstDesc::MRK_UIntMin);
+    return RecurrenceInstDesc(Select, RecurrenceInstDesc::MRK_UIntMin);
   else if (m_UMax(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
-    return ReductionInstDesc(Select, ReductionInstDesc::MRK_UIntMax);
+    return RecurrenceInstDesc(Select, RecurrenceInstDesc::MRK_UIntMax);
   else if (m_SMax(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
-    return ReductionInstDesc(Select, ReductionInstDesc::MRK_SIntMax);
+    return RecurrenceInstDesc(Select, RecurrenceInstDesc::MRK_SIntMax);
   else if (m_SMin(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
-    return ReductionInstDesc(Select, ReductionInstDesc::MRK_SIntMin);
+    return RecurrenceInstDesc(Select, RecurrenceInstDesc::MRK_SIntMin);
   else if (m_OrdFMin(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
-    return ReductionInstDesc(Select, ReductionInstDesc::MRK_FloatMin);
+    return RecurrenceInstDesc(Select, RecurrenceInstDesc::MRK_FloatMin);
   else if (m_OrdFMax(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
-    return ReductionInstDesc(Select, ReductionInstDesc::MRK_FloatMax);
+    return RecurrenceInstDesc(Select, RecurrenceInstDesc::MRK_FloatMax);
   else if (m_UnordFMin(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
-    return ReductionInstDesc(Select, ReductionInstDesc::MRK_FloatMin);
+    return RecurrenceInstDesc(Select, RecurrenceInstDesc::MRK_FloatMin);
   else if (m_UnordFMax(m_Value(CmpLeft), m_Value(CmpRight)).match(Select))
-    return ReductionInstDesc(Select, ReductionInstDesc::MRK_FloatMax);
+    return RecurrenceInstDesc(Select, RecurrenceInstDesc::MRK_FloatMax);
 
-  return ReductionInstDesc(false, I);
+  return RecurrenceInstDesc(false, I);
 }
 
-ReductionInstDesc ReductionDescriptor::isReductionInstr(Instruction *I,
-                                                        ReductionKind Kind,
-                                                        ReductionInstDesc &Prev,
-                                                        bool HasFunNoNaNAttr) {
+RecurrenceInstDesc
+RecurrenceDescriptor::isRecurrenceInstr(Instruction *I, RecurrenceKind Kind,
+                                        RecurrenceInstDesc &Prev,
+                                        bool HasFunNoNaNAttr) {
   bool FP = I->getType()->isFloatingPointTy();
   bool FastMath = FP && I->hasUnsafeAlgebra();
   switch (I->getOpcode()) {
   default:
-    return ReductionInstDesc(false, I);
+    return RecurrenceInstDesc(false, I);
   case Instruction::PHI:
     if (FP &&
         (Kind != RK_FloatMult && Kind != RK_FloatAdd && Kind != RK_FloatMinMax))
-      return ReductionInstDesc(false, I);
-    return ReductionInstDesc(I, Prev.getMinMaxKind());
+      return RecurrenceInstDesc(false, I);
+    return RecurrenceInstDesc(I, Prev.getMinMaxKind());
   case Instruction::Sub:
   case Instruction::Add:
-    return ReductionInstDesc(Kind == RK_IntegerAdd, I);
+    return RecurrenceInstDesc(Kind == RK_IntegerAdd, I);
   case Instruction::Mul:
-    return ReductionInstDesc(Kind == RK_IntegerMult, I);
+    return RecurrenceInstDesc(Kind == RK_IntegerMult, I);
   case Instruction::And:
-    return ReductionInstDesc(Kind == RK_IntegerAnd, I);
+    return RecurrenceInstDesc(Kind == RK_IntegerAnd, I);
   case Instruction::Or:
-    return ReductionInstDesc(Kind == RK_IntegerOr, I);
+    return RecurrenceInstDesc(Kind == RK_IntegerOr, I);
   case Instruction::Xor:
-    return ReductionInstDesc(Kind == RK_IntegerXor, I);
+    return RecurrenceInstDesc(Kind == RK_IntegerXor, I);
   case Instruction::FMul:
-    return ReductionInstDesc(Kind == RK_FloatMult && FastMath, I);
+    return RecurrenceInstDesc(Kind == RK_FloatMult && FastMath, I);
   case Instruction::FSub:
   case Instruction::FAdd:
-    return ReductionInstDesc(Kind == RK_FloatAdd && FastMath, I);
+    return RecurrenceInstDesc(Kind == RK_FloatAdd && FastMath, I);
   case Instruction::FCmp:
   case Instruction::ICmp:
   case Instruction::Select:
     if (Kind != RK_IntegerMinMax &&
         (!HasFunNoNaNAttr || Kind != RK_FloatMinMax))
-      return ReductionInstDesc(false, I);
+      return RecurrenceInstDesc(false, I);
     return isMinMaxSelectCmpPattern(I, Prev);
   }
 }
 
-bool ReductionDescriptor::hasMultipleUsesOf(
+bool RecurrenceDescriptor::hasMultipleUsesOf(
     Instruction *I, SmallPtrSetImpl<Instruction *> &Insts) {
   unsigned NumUses = 0;
   for (User::op_iterator Use = I->op_begin(), E = I->op_end(); Use != E;
@@ -313,8 +313,8 @@ bool ReductionDescriptor::hasMultipleUsesOf(
 
   return false;
 }
-bool ReductionDescriptor::isReductionPHI(PHINode *Phi, Loop *TheLoop,
-                                         ReductionDescriptor &RedDes) {
+bool RecurrenceDescriptor::isReductionPHI(PHINode *Phi, Loop *TheLoop,
+                                          RecurrenceDescriptor &RedDes) {
 
   bool HasFunNoNaNAttr = false;
   BasicBlock *Header = TheLoop->getHeader();
@@ -366,7 +366,8 @@ bool ReductionDescriptor::isReductionPHI(PHINode *Phi, Loop *TheLoop,
 
 /// This function returns the identity element (or neutral element) for
 /// the operation K.
-Constant *ReductionDescriptor::getReductionIdentity(ReductionKind K, Type *Tp) {
+Constant *RecurrenceDescriptor::getRecurrenceIdentity(RecurrenceKind K,
+                                                      Type *Tp) {
   switch (K) {
   case RK_IntegerXor:
   case RK_IntegerAdd:
@@ -386,12 +387,12 @@ Constant *ReductionDescriptor::getReductionIdentity(ReductionKind K, Type *Tp) {
     // Adding zero to a number does not change it.
     return ConstantFP::get(Tp, 0.0L);
   default:
-    llvm_unreachable("Unknown reduction kind");
+    llvm_unreachable("Unknown recurrence kind");
   }
 }
 
-/// This function translates the reduction kind to an LLVM binary operator.
-unsigned ReductionDescriptor::getReductionBinOp(ReductionKind Kind) {
+/// This function translates the recurrence kind to an LLVM binary operator.
+unsigned RecurrenceDescriptor::getRecurrenceBinOp(RecurrenceKind Kind) {
   switch (Kind) {
   case RK_IntegerAdd:
     return Instruction::Add;
@@ -412,41 +413,40 @@ unsigned ReductionDescriptor::getReductionBinOp(ReductionKind Kind) {
   case RK_FloatMinMax:
     return Instruction::FCmp;
   default:
-    llvm_unreachable("Unknown reduction operation");
+    llvm_unreachable("Unknown recurrence operation");
   }
 }
 
-Value *
-ReductionDescriptor::createMinMaxOp(IRBuilder<> &Builder,
-                                    ReductionInstDesc::MinMaxReductionKind RK,
-                                    Value *Left, Value *Right) {
+Value *RecurrenceDescriptor::createMinMaxOp(
+    IRBuilder<> &Builder, RecurrenceInstDesc::MinMaxRecurrenceKind RK,
+    Value *Left, Value *Right) {
   CmpInst::Predicate P = CmpInst::ICMP_NE;
   switch (RK) {
   default:
-    llvm_unreachable("Unknown min/max reduction kind");
-  case ReductionInstDesc::MRK_UIntMin:
+    llvm_unreachable("Unknown min/max recurrence kind");
+  case RecurrenceInstDesc::MRK_UIntMin:
     P = CmpInst::ICMP_ULT;
     break;
-  case ReductionInstDesc::MRK_UIntMax:
+  case RecurrenceInstDesc::MRK_UIntMax:
     P = CmpInst::ICMP_UGT;
     break;
-  case ReductionInstDesc::MRK_SIntMin:
+  case RecurrenceInstDesc::MRK_SIntMin:
     P = CmpInst::ICMP_SLT;
     break;
-  case ReductionInstDesc::MRK_SIntMax:
+  case RecurrenceInstDesc::MRK_SIntMax:
     P = CmpInst::ICMP_SGT;
     break;
-  case ReductionInstDesc::MRK_FloatMin:
+  case RecurrenceInstDesc::MRK_FloatMin:
     P = CmpInst::FCMP_OLT;
     break;
-  case ReductionInstDesc::MRK_FloatMax:
+  case RecurrenceInstDesc::MRK_FloatMax:
     P = CmpInst::FCMP_OGT;
     break;
   }
 
   Value *Cmp;
-  if (RK == ReductionInstDesc::MRK_FloatMin ||
-      RK == ReductionInstDesc::MRK_FloatMax)
+  if (RK == RecurrenceInstDesc::MRK_FloatMin ||
+      RK == RecurrenceInstDesc::MRK_FloatMax)
     Cmp = Builder.CreateFCmp(P, Left, Right, "rdx.minmax.cmp");
   else
     Cmp = Builder.CreateICmp(P, Left, Right, "rdx.minmax.cmp");
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 95c9381..62de200 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -872,7 +872,7 @@ public:
 
   /// ReductionList contains the reduction descriptors for all
   /// of the reductions that were found in the loop.
-  typedef DenseMap<PHINode*, ReductionDescriptor> ReductionList;
+  typedef DenseMap<PHINode *, RecurrenceDescriptor> ReductionList;
 
   /// InductionList saves induction variables and maps them to the
   /// induction descriptor.
@@ -3093,13 +3093,13 @@ void InnerLoopVectorizer::vectorizeLoop() {
     // Find the reduction variable descriptor.
     assert(Legal->getReductionVars()->count(RdxPhi) &&
            "Unable to find the reduction variable");
-    ReductionDescriptor RdxDesc = (*Legal->getReductionVars())[RdxPhi];
+    RecurrenceDescriptor RdxDesc = (*Legal->getReductionVars())[RdxPhi];
 
-    ReductionDescriptor::ReductionKind RK = RdxDesc.getReductionKind();
-    TrackingVH<Value> ReductionStartValue = RdxDesc.getReductionStartValue();
+    RecurrenceDescriptor::RecurrenceKind RK = RdxDesc.getRecurrenceKind();
+    TrackingVH<Value> ReductionStartValue = RdxDesc.getRecurrenceStartValue();
     Instruction *LoopExitInst = RdxDesc.getLoopExitInstr();
-    ReductionInstDesc::MinMaxReductionKind MinMaxKind =
-        RdxDesc.getMinMaxReductionKind();
+    RecurrenceInstDesc::MinMaxRecurrenceKind MinMaxKind =
+        RdxDesc.getMinMaxRecurrenceKind();
     setDebugLocFromInst(Builder, ReductionStartValue);
 
     // We need to generate a reduction vector from the incoming scalar.
@@ -3116,8 +3116,8 @@ void InnerLoopVectorizer::vectorizeLoop() {
     // one for multiplication, -1 for And.
     Value *Identity;
     Value *VectorStart;
-    if (RK == ReductionDescriptor::RK_IntegerMinMax ||
-        RK == ReductionDescriptor::RK_FloatMinMax) {
+    if (RK == RecurrenceDescriptor::RK_IntegerMinMax ||
+        RK == RecurrenceDescriptor::RK_FloatMinMax) {
       // MinMax reduction have the start value as their identify.
       if (VF == 1) {
         VectorStart = Identity = ReductionStartValue;
@@ -3127,8 +3127,8 @@ void InnerLoopVectorizer::vectorizeLoop() {
       }
     } else {
       // Handle other reduction kinds:
-      Constant *Iden =
-          ReductionDescriptor::getReductionIdentity(RK, VecTy->getScalarType());
+      Constant *Iden = RecurrenceDescriptor::getRecurrenceIdentity(
+          RK, VecTy->getScalarType());
       if (VF == 1) {
         Identity = Iden;
         // This vector is the Identity vector where the first element is the
@@ -3185,7 +3185,7 @@ void InnerLoopVectorizer::vectorizeLoop() {
 
     // Reduce all of the unrolled parts into a single vector.
     Value *ReducedPartRdx = RdxParts[0];
-    unsigned Op = ReductionDescriptor::getReductionBinOp(RK);
+    unsigned Op = RecurrenceDescriptor::getRecurrenceBinOp(RK);
     setDebugLocFromInst(Builder, ReducedPartRdx);
     for (unsigned part = 1; part < UF; ++part) {
       if (Op != Instruction::ICmp && Op != Instruction::FCmp)
@@ -3194,7 +3194,7 @@ void InnerLoopVectorizer::vectorizeLoop() {
             Builder.CreateBinOp((Instruction::BinaryOps)Op, RdxParts[part],
                                 ReducedPartRdx, "bin.rdx"));
       else
-        ReducedPartRdx = ReductionDescriptor::createMinMaxOp(
+        ReducedPartRdx = RecurrenceDescriptor::createMinMaxOp(
             Builder, MinMaxKind, ReducedPartRdx, RdxParts[part]);
     }
 
@@ -3226,8 +3226,8 @@ void InnerLoopVectorizer::vectorizeLoop() {
           TmpVec = addFastMathFlag(Builder.CreateBinOp(
               (Instruction::BinaryOps)Op, TmpVec, Shuf, "bin.rdx"));
         else
-          TmpVec = ReductionDescriptor::createMinMaxOp(Builder, MinMaxKind,
-                                                       TmpVec, Shuf);
+          TmpVec = RecurrenceDescriptor::createMinMaxOp(Builder, MinMaxKind,
+                                                        TmpVec, Shuf);
       }
 
       // The result is in the first element of the vector.
@@ -4040,8 +4040,8 @@ bool LoopVectorizationLegality::canVectorizeInstrs() {
           continue;
         }
 
-        if (ReductionDescriptor::isReductionPHI(Phi, TheLoop,
-                                                Reductions[Phi])) {
+        if (RecurrenceDescriptor::isReductionPHI(Phi, TheLoop,
+                                                 Reductions[Phi])) {
           AllowedExit.insert(Reductions[Phi].getLoopExitInstr());
           continue;
         }