[NFC] Separate Peeling Properties into its own struct

Summary:
This patch makes the peeling properties of the loop accessible by other loop transformations.

Author: sidbav (Sidharth Baveja)

Reviewers: Whitney (Whitney Tsang), Meinersbur (Michael Kruse), skatkov (Serguei Katkov), ashlykov (Arkady Shlykov), bogner (Justin Bogner), hfinkel (Hal Finkel)

Reviewed By: Meinersbur (Michael Kruse)

Subscribers: fhahn (Florian Hahn), hiraditya (Aditya Kumar), llvm-commits, LLVM

Tag: LLVM

Differential Revision: https://reviews.llvm.org/D80580

include/llvm/Analysis/TargetTransformInfo.h

@@ -450,11 +450,6 @@ public:
     /// transformation will select an unrolling factor based on the current cost
     /// threshold and other factors.
     unsigned Count;
-    /// A forced peeling factor (the number of bodied of the original loop
-    /// that should be peeled off before the loop body). When set to 0, the
-    /// unrolling transformation will select a peeling factor based on profile
-    /// information and other factors.
-    unsigned PeelCount;
     /// Default unroll count for loops with run-time trip count.
     unsigned DefaultUnrollRuntimeCount;
     // Set the maximum unrolling factor. The unrolling factor may be selected
@@ -488,19 +483,10 @@ public:
     bool Force;
     /// Allow using trip count upper bound to unroll loops.
     bool UpperBound;
-    /// Allow peeling off loop iterations.
-    bool AllowPeeling;
-    /// Allow peeling off loop iterations for loop nests.
-    bool AllowLoopNestsPeeling;
     /// Allow unrolling of all the iterations of the runtime loop remainder.
     bool UnrollRemainder;
     /// Allow unroll and jam. Used to enable unroll and jam for the target.
     bool UnrollAndJam;
-    /// Allow peeling basing on profile. Uses to enable peeling off all
-    /// iterations basing on provided profile.
-    /// If the value is true the peeling cost model can decide to peel only
-    /// some iterations and in this case it will set this to false.
-    bool PeelProfiledIterations;
     /// Threshold for unroll and jam, for inner loop size. The 'Threshold'
     /// value above is used during unroll and jam for the outer loop size.
     /// This value is used in the same manner to limit the size of the inner
@@ -534,6 +520,28 @@ public:
   /// intrinsic is supported.
   bool emitGetActiveLaneMask() const;
 
+  // Parameters that control the loop peeling transformation
+  struct PeelingPreferences {
+    /// A forced peeling factor (the number of bodied of the original loop
+    /// that should be peeled off before the loop body). When set to 0, the
+    /// a peeling factor based on profile information and other factors.
+    unsigned PeelCount;
+    /// Allow peeling off loop iterations.
+    bool AllowPeeling;
+    /// Allow peeling off loop iterations for loop nests.
+    bool AllowLoopNestsPeeling;
+    /// Allow peeling basing on profile. Uses to enable peeling off all
+    /// iterations basing on provided profile.
+    /// If the value is true the peeling cost model can decide to peel only
+    /// some iterations and in this case it will set this to false.
+    bool PeelProfiledIterations;
+  };
+
+  /// Get target-customized preferences for the generic loop peeling
+  /// transformation. The caller will initialize \p PP with the current
+  /// target-independent defaults with information from \p L and \p SE.
+  void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                             PeelingPreferences &PP) const;
   /// @}
 
   /// \name Scalar Target Information
@@ -1282,6 +1290,8 @@ public:
   virtual bool isLoweredToCall(const Function *F) = 0;
   virtual void getUnrollingPreferences(Loop *L, ScalarEvolution &,
                                        UnrollingPreferences &UP) = 0;
+  virtual void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                                     PeelingPreferences &PP) = 0;
   virtual bool isHardwareLoopProfitable(Loop *L, ScalarEvolution &SE,
                                         AssumptionCache &AC,
                                         TargetLibraryInfo *LibInfo,
@@ -1560,6 +1570,10 @@ public:
                                UnrollingPreferences &UP) override {
     return Impl.getUnrollingPreferences(L, SE, UP);
   }
+  void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                             PeelingPreferences &PP) override {
+    return Impl.getPeelingPreferences(L, SE, PP);
+  }
   bool isHardwareLoopProfitable(Loop *L, ScalarEvolution &SE,
                                 AssumptionCache &AC, TargetLibraryInfo *LibInfo,
                                 HardwareLoopInfo &HWLoopInfo) override {

include/llvm/Analysis/TargetTransformInfoImpl.h

@@ -150,6 +150,9 @@ public:
   void getUnrollingPreferences(Loop *, ScalarEvolution &,
                                TTI::UnrollingPreferences &) {}
 
+  void getPeelingPreferences(Loop *, ScalarEvolution &,
+                             TTI::PeelingPreferences &) {}
+
   bool isLegalAddImmediate(int64_t Imm) { return false; }
 
   bool isLegalICmpImmediate(int64_t Imm) { return false; }

include/llvm/CodeGen/BasicTTIImpl.h

@@ -451,6 +451,14 @@ public:
     UP.BEInsns = 2;
   }
 
+  void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                             TTI::PeelingPreferences &PP) {
+    PP.PeelCount = 0;
+    PP.AllowPeeling = true;
+    PP.AllowLoopNestsPeeling = false;
+    PP.PeelProfiledIterations = true;
+  }
+
   bool isHardwareLoopProfitable(Loop *L, ScalarEvolution &SE,
                                 AssumptionCache &AC,
                                 TargetLibraryInfo *LibInfo,

include/llvm/Transforms/Utils/UnrollLoop.h

@@ -94,6 +94,7 @@ bool UnrollRuntimeLoopRemainder(
 
 void computePeelCount(Loop *L, unsigned LoopSize,
                       TargetTransformInfo::UnrollingPreferences &UP,
+                      TargetTransformInfo::PeelingPreferences &PP,
                       unsigned &TripCount, ScalarEvolution &SE);
 
 bool canPeel(Loop *L);
@@ -119,6 +120,8 @@ bool computeUnrollCount(Loop *L, const TargetTransformInfo &TTI,
                         unsigned MaxTripCount, bool MaxOrZero,
                         unsigned &TripMultiple, unsigned LoopSize,
                         TargetTransformInfo::UnrollingPreferences &UP,
+                        TargetTransformInfo::PeelingPreferences &PP,
+
                         bool &UseUpperBound);
 
 void simplifyLoopAfterUnroll(Loop *L, bool SimplifyIVs, LoopInfo *LI,
@@ -133,9 +136,13 @@ TargetTransformInfo::UnrollingPreferences gatherUnrollingPreferences(
     BlockFrequencyInfo *BFI, ProfileSummaryInfo *PSI, int OptLevel,
     Optional<unsigned> UserThreshold, Optional<unsigned> UserCount,
     Optional<bool> UserAllowPartial, Optional<bool> UserRuntime,
-    Optional<bool> UserUpperBound, Optional<bool> UserAllowPeeling,
-    Optional<bool> UserAllowProfileBasedPeeling,
-    Optional<unsigned> UserFullUnrollMaxCount);
+    Optional<bool> UserUpperBound, Optional<unsigned> UserFullUnrollMaxCount);
+
+TargetTransformInfo::PeelingPreferences
+gatherPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                         const TargetTransformInfo &TTI,
+                         Optional<bool> UserAllowPeeling,
+                         Optional<bool> UserAllowProfileBasedPeeling);
 
 unsigned ApproximateLoopSize(const Loop *L, unsigned &NumCalls,
                              bool &NotDuplicatable, bool &Convergent,

lib/Analysis/TargetTransformInfo.cpp

@@ -327,6 +327,11 @@ void TargetTransformInfo::getUnrollingPreferences(
   return TTIImpl->getUnrollingPreferences(L, SE, UP);
 }
 
+void TargetTransformInfo::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                                                PeelingPreferences &PP) const {
+  return TTIImpl->getPeelingPreferences(L, SE, PP);
+}
+
 bool TargetTransformInfo::isLegalAddImmediate(int64_t Imm) const {
   return TTIImpl->isLegalAddImmediate(Imm);
 }

lib/Target/AArch64/AArch64TargetTransformInfo.cpp

@@ -859,6 +859,11 @@ void AArch64TTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
     getFalkorUnrollingPreferences(L, SE, UP);
 }
 
+void AArch64TTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                                           TTI::PeelingPreferences &PP) {
+  BaseT::getPeelingPreferences(L, SE, PP);
+}
+
 Value *AArch64TTIImpl::getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
                                                          Type *ExpectedType) {
   switch (Inst->getIntrinsicID()) {

lib/Target/AArch64/AArch64TargetTransformInfo.h

@@ -153,6 +153,9 @@ public:
   void getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                TTI::UnrollingPreferences &UP);
 
+  void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                             TTI::PeelingPreferences &PP);
+
   Value *getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
                                            Type *ExpectedType);
 

lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp

@@ -236,6 +236,10 @@ void AMDGPUTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
   }
 }
 
+void AMDGPUTTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                                          TTI::PeelingPreferences &PP) {
+  BaseT::getPeelingPreferences(L, SE, PP);
+}
 unsigned GCNTTIImpl::getHardwareNumberOfRegisters(bool Vec) const {
   // The concept of vector registers doesn't really exist. Some packed vector
   // operations operate on the normal 32-bit registers.
@@ -990,6 +994,11 @@ void GCNTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
   CommonTTI.getUnrollingPreferences(L, SE, UP);
 }
 
+void GCNTTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                                       TTI::PeelingPreferences &PP) {
+  CommonTTI.getPeelingPreferences(L, SE, PP);
+}
+
 unsigned R600TTIImpl::getHardwareNumberOfRegisters(bool Vec) const {
   return 4 * 128; // XXX - 4 channels. Should these count as vector instead?
 }
@@ -1096,3 +1105,8 @@ void R600TTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                           TTI::UnrollingPreferences &UP) {
   CommonTTI.getUnrollingPreferences(L, SE, UP);
 }
+
+void R600TTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                                        TTI::PeelingPreferences &PP) {
+  CommonTTI.getPeelingPreferences(L, SE, PP);
+}

lib/Target/AMDGPU/AMDGPUTargetTransformInfo.h

@@ -61,6 +61,9 @@ public:
 
   void getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                TTI::UnrollingPreferences &UP);
+
+  void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                             TTI::PeelingPreferences &PP);
 };
 
 class GCNTTIImpl final : public BasicTTIImplBase<GCNTTIImpl> {
@@ -141,6 +144,9 @@ public:
   void getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                TTI::UnrollingPreferences &UP);
 
+  void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                             TTI::PeelingPreferences &PP);
+
   TTI::PopcntSupportKind getPopcntSupport(unsigned TyWidth) {
     assert(isPowerOf2_32(TyWidth) && "Ty width must be power of 2");
     return TTI::PSK_FastHardware;
@@ -258,6 +264,8 @@ public:
 
   void getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                TTI::UnrollingPreferences &UP);
+  void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                             TTI::PeelingPreferences &PP);
   unsigned getHardwareNumberOfRegisters(bool Vec) const;
   unsigned getNumberOfRegisters(bool Vec) const;
   unsigned getRegisterBitWidth(bool Vector) const;

lib/Target/ARM/ARMTargetTransformInfo.cpp

@@ -1582,6 +1582,11 @@ void ARMTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
     UP.Force = true;
 }
 
+void ARMTTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                                       TTI::PeelingPreferences &PP) {
+  BaseT::getPeelingPreferences(L, SE, PP);
+}
+
 bool ARMTTIImpl::useReductionIntrinsic(unsigned Opcode, Type *Ty,
                                        TTI::ReductionFlags Flags) const {
   return ST->hasMVEIntegerOps();

lib/Target/ARM/ARMTargetTransformInfo.h

@@ -251,6 +251,8 @@ public:
 
   bool emitGetActiveLaneMask() const;
 
+  void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                             TTI::PeelingPreferences &PP);
   bool shouldBuildLookupTablesForConstant(Constant *C) const {
     // In the ROPI and RWPI relocation models we can't have pointers to global
     // variables or functions in constant data, so don't convert switches to

lib/Target/Hexagon/HexagonTargetTransformInfo.cpp

@@ -78,12 +78,17 @@ HexagonTTIImpl::getPopcntSupport(unsigned IntTyWidthInBit) const {
 void HexagonTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                              TTI::UnrollingPreferences &UP) {
   UP.Runtime = UP.Partial = true;
+}
+
+void HexagonTTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                                           TTI::PeelingPreferences &PP) {
+  BaseT::getPeelingPreferences(L, SE, PP);
   // Only try to peel innermost loops with small runtime trip counts.
   if (L && L->empty() && canPeel(L) &&
       SE.getSmallConstantTripCount(L) == 0 &&
       SE.getSmallConstantMaxTripCount(L) > 0 &&
       SE.getSmallConstantMaxTripCount(L) <= 5) {
-    UP.PeelCount = 2;
+    PP.PeelCount = 2;
   }
 }
 

lib/Target/Hexagon/HexagonTargetTransformInfo.h

@@ -64,6 +64,9 @@ public:
   void getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                TTI::UnrollingPreferences &UP);
 
+  void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                             TTI::PeelingPreferences &PP);
+
   /// Bias LSR towards creating post-increment opportunities.
   bool shouldFavorPostInc() const;
 

lib/Target/NVPTX/NVPTXTargetTransformInfo.cpp

@@ -155,3 +155,8 @@ void NVPTXTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
   UP.Partial = UP.Runtime = true;
   UP.PartialThreshold = UP.Threshold / 4;
 }
+
+void NVPTXTTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                                         TTI::PeelingPreferences &PP) {
+  BaseT::getPeelingPreferences(L, SE, PP);
+}

lib/Target/NVPTX/NVPTXTargetTransformInfo.h

@@ -95,6 +95,10 @@ public:
 
   void getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                TTI::UnrollingPreferences &UP);
+
+  void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                             TTI::PeelingPreferences &PP);
+
   bool hasVolatileVariant(Instruction *I, unsigned AddrSpace) {
     // Volatile loads/stores are only supported for shared and global address
     // spaces, or for generic AS that maps to them.

lib/Target/PowerPC/PPCTargetTransformInfo.cpp

@@ -568,6 +568,10 @@ void PPCTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
   BaseT::getUnrollingPreferences(L, SE, UP);
 }
 
+void PPCTTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                                       TTI::PeelingPreferences &PP) {
+  BaseT::getPeelingPreferences(L, SE, PP);
+}
 // This function returns true to allow using coldcc calling convention.
 // Returning true results in coldcc being used for functions which are cold at
 // all call sites when the callers of the functions are not calling any other

lib/Target/PowerPC/PPCTargetTransformInfo.h

@@ -66,6 +66,8 @@ public:
                   TargetLibraryInfo *LibInfo);
   void getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                TTI::UnrollingPreferences &UP);
+  void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                             TTI::PeelingPreferences &PP);
   bool isLSRCostLess(TargetTransformInfo::LSRCost &C1,
                      TargetTransformInfo::LSRCost &C2);
 

lib/Target/SystemZ/SystemZTargetTransformInfo.cpp

@@ -294,6 +294,10 @@ void SystemZTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
   UP.Force = true;
 }
 
+void SystemZTTIImpl::getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                                           TTI::PeelingPreferences &PP) {
+  BaseT::getPeelingPreferences(L, SE, PP);
+}
 
 bool SystemZTTIImpl::isLSRCostLess(TargetTransformInfo::LSRCost &C1,
                                    TargetTransformInfo::LSRCost &C2) {

lib/Target/SystemZ/SystemZTargetTransformInfo.h

@@ -50,6 +50,9 @@ public:
   void getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                TTI::UnrollingPreferences &UP);
 
+  void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                             TTI::PeelingPreferences &PP);
+
   bool isLSRCostLess(TargetTransformInfo::LSRCost &C1,
                      TargetTransformInfo::LSRCost &C2);
   /// @}

lib/Transforms/Scalar/LoopUnrollAndJamPass.cpp

@@ -158,7 +158,8 @@ static bool computeUnrollAndJamCount(
     const SmallPtrSetImpl<const Value *> &EphValues,
     OptimizationRemarkEmitter *ORE, unsigned OuterTripCount,
     unsigned OuterTripMultiple, unsigned OuterLoopSize, unsigned InnerTripCount,
-    unsigned InnerLoopSize, TargetTransformInfo::UnrollingPreferences &UP) {
+    unsigned InnerLoopSize, TargetTransformInfo::UnrollingPreferences &UP,
+    TargetTransformInfo::PeelingPreferences &PP) {
   // First up use computeUnrollCount from the loop unroller to get a count
   // for unrolling the outer loop, plus any loops requiring explicit
   // unrolling we leave to the unroller. This uses UP.Threshold /
@@ -168,7 +169,8 @@ static bool computeUnrollAndJamCount(
   bool UseUpperBound = false;
   bool ExplicitUnroll = computeUnrollCount(
       L, TTI, DT, LI, SE, EphValues, ORE, OuterTripCount, MaxTripCount,
-      /*MaxOrZero*/ false, OuterTripMultiple, OuterLoopSize, UP, UseUpperBound);
+      /*MaxOrZero*/ false, OuterTripMultiple, OuterLoopSize, UP, PP,
+      UseUpperBound);
   if (ExplicitUnroll || UseUpperBound) {
     // If the user explicitly set the loop as unrolled, dont UnJ it. Leave it
     // for the unroller instead.
@@ -282,7 +284,9 @@ tryToUnrollAndJamLoop(Loop *L, DominatorTree &DT, LoopInfo *LI,
                       OptimizationRemarkEmitter &ORE, int OptLevel) {
   TargetTransformInfo::UnrollingPreferences UP =
       gatherUnrollingPreferences(L, SE, TTI, nullptr, nullptr, OptLevel, None,
-                                 None, None, None, None, None, None, None);
+                                 None, None, None, None, None);
+  TargetTransformInfo::PeelingPreferences PP =
+      gatherPeelingPreferences(L, SE, TTI, None, None);
   if (AllowUnrollAndJam.getNumOccurrences() > 0)
     UP.UnrollAndJam = AllowUnrollAndJam;
   if (UnrollAndJamThreshold.getNumOccurrences() > 0)
@@ -367,7 +371,7 @@ tryToUnrollAndJamLoop(Loop *L, DominatorTree &DT, LoopInfo *LI,
   // Decide if, and by how much, to unroll
   bool IsCountSetExplicitly = computeUnrollAndJamCount(
       L, SubLoop, TTI, DT, LI, SE, EphValues, &ORE, OuterTripCount,
-      OuterTripMultiple, OuterLoopSize, InnerTripCount, InnerLoopSize, UP);
+      OuterTripMultiple, OuterLoopSize, InnerTripCount, InnerLoopSize, UP, PP);
   if (UP.Count <= 1)
     return LoopUnrollResult::Unmodified;
   // Unroll factor (Count) must be less or equal to TripCount.

lib/Transforms/Scalar/LoopUnrollPass.cpp

@@ -193,9 +193,7 @@ TargetTransformInfo::UnrollingPreferences llvm::gatherUnrollingPreferences(
     BlockFrequencyInfo *BFI, ProfileSummaryInfo *PSI, int OptLevel,
     Optional<unsigned> UserThreshold, Optional<unsigned> UserCount,
     Optional<bool> UserAllowPartial, Optional<bool> UserRuntime,
-    Optional<bool> UserUpperBound, Optional<bool> UserAllowPeeling,
-    Optional<bool> UserAllowProfileBasedPeeling,
-    Optional<unsigned> UserFullUnrollMaxCount) {
+    Optional<bool> UserUpperBound, Optional<unsigned> UserFullUnrollMaxCount) {
   TargetTransformInfo::UnrollingPreferences UP;
 
   // Set up the defaults
@@ -206,7 +204,6 @@ TargetTransformInfo::UnrollingPreferences llvm::gatherUnrollingPreferences(
   UP.PartialThreshold = 150;
   UP.PartialOptSizeThreshold = 0;
   UP.Count = 0;
-  UP.PeelCount = 0;
   UP.DefaultUnrollRuntimeCount = 8;
   UP.MaxCount = std::numeric_limits<unsigned>::max();
   UP.FullUnrollMaxCount = std::numeric_limits<unsigned>::max();
@@ -218,10 +215,7 @@ TargetTransformInfo::UnrollingPreferences llvm::gatherUnrollingPreferences(
   UP.AllowExpensiveTripCount = false;
   UP.Force = false;
   UP.UpperBound = false;
-  UP.AllowPeeling = true;
-  UP.AllowLoopNestsPeeling = false;
   UP.UnrollAndJam = false;
-  UP.PeelProfiledIterations = true;
   UP.UnrollAndJamInnerLoopThreshold = 60;
   UP.MaxIterationsCountToAnalyze = UnrollMaxIterationsCountToAnalyze;
 
@@ -249,8 +243,6 @@ TargetTransformInfo::UnrollingPreferences llvm::gatherUnrollingPreferences(
     UP.MaxCount = UnrollMaxCount;
   if (UnrollFullMaxCount.getNumOccurrences() > 0)
     UP.FullUnrollMaxCount = UnrollFullMaxCount;
-  if (UnrollPeelCount.getNumOccurrences() > 0)
-    UP.PeelCount = UnrollPeelCount;
   if (UnrollAllowPartial.getNumOccurrences() > 0)
     UP.Partial = UnrollAllowPartial;
   if (UnrollAllowRemainder.getNumOccurrences() > 0)
@@ -259,10 +251,6 @@ TargetTransformInfo::UnrollingPreferences llvm::gatherUnrollingPreferences(
     UP.Runtime = UnrollRuntime;
   if (UnrollMaxUpperBound == 0)
     UP.UpperBound = false;
-  if (UnrollAllowPeeling.getNumOccurrences() > 0)
-    UP.AllowPeeling = UnrollAllowPeeling;
-  if (UnrollAllowLoopNestsPeeling.getNumOccurrences() > 0)
-    UP.AllowLoopNestsPeeling = UnrollAllowLoopNestsPeeling;
   if (UnrollUnrollRemainder.getNumOccurrences() > 0)
     UP.UnrollRemainder = UnrollUnrollRemainder;
   if (UnrollMaxIterationsCountToAnalyze.getNumOccurrences() > 0)
@@ -281,16 +269,39 @@ TargetTransformInfo::UnrollingPreferences llvm::gatherUnrollingPreferences(
     UP.Runtime = *UserRuntime;
   if (UserUpperBound.hasValue())
     UP.UpperBound = *UserUpperBound;
-  if (UserAllowPeeling.hasValue())
-    UP.AllowPeeling = *UserAllowPeeling;
-  if (UserAllowProfileBasedPeeling.hasValue())
-    UP.PeelProfiledIterations = *UserAllowProfileBasedPeeling;
   if (UserFullUnrollMaxCount.hasValue())
     UP.FullUnrollMaxCount = *UserFullUnrollMaxCount;
 
   return UP;
 }
 
+TargetTransformInfo::PeelingPreferences
+llvm::gatherPeelingPreferences(Loop *L, ScalarEvolution &SE,
+                               const TargetTransformInfo &TTI,
+                               Optional<bool> UserAllowPeeling,
+                               Optional<bool> UserAllowProfileBasedPeeling) {
+  TargetTransformInfo::PeelingPreferences PP;
+
+  // Get Target Specifc Values
+  TTI.getPeelingPreferences(L, SE, PP);
+
+  // User Specified Values using cl::opt
+  if (UnrollPeelCount.getNumOccurrences() > 0)
+    PP.PeelCount = UnrollPeelCount;
+  if (UnrollAllowPeeling.getNumOccurrences() > 0)
+    PP.AllowPeeling = UnrollAllowPeeling;
+  if (UnrollAllowLoopNestsPeeling.getNumOccurrences() > 0)
+    PP.AllowLoopNestsPeeling = UnrollAllowLoopNestsPeeling;
+
+  // User Specifed values provided by argument
+  if (UserAllowPeeling.hasValue())
+    PP.AllowPeeling = *UserAllowPeeling;
+  if (UserAllowProfileBasedPeeling.hasValue())
+    PP.PeelProfiledIterations = *UserAllowProfileBasedPeeling;
+
+  return PP;
+}
+
 namespace {
 
 /// A struct to densely store the state of an instruction after unrolling at
@@ -761,7 +772,8 @@ bool llvm::computeUnrollCount(
     ScalarEvolution &SE, const SmallPtrSetImpl<const Value *> &EphValues,
     OptimizationRemarkEmitter *ORE, unsigned &TripCount, unsigned MaxTripCount,
     bool MaxOrZero, unsigned &TripMultiple, unsigned LoopSize,
-    TargetTransformInfo::UnrollingPreferences &UP, bool &UseUpperBound) {
+    TargetTransformInfo::UnrollingPreferences &UP,
+    TargetTransformInfo::PeelingPreferences &PP, bool &UseUpperBound) {
 
   // Check for explicit Count.
   // 1st priority is unroll count set by "unroll-count" option.
@@ -863,8 +875,8 @@ bool llvm::computeUnrollCount(
   }
 
   // 4th priority is loop peeling.
-  computePeelCount(L, LoopSize, UP, TripCount, SE);
-  if (UP.PeelCount) {
+  computePeelCount(L, LoopSize, UP, PP, TripCount, SE);
+  if (PP.PeelCount) {
     UP.Runtime = false;
     UP.Count = 1;
     return ExplicitUnroll;
@@ -1067,8 +1079,9 @@ static LoopUnrollResult tryToUnrollLoop(
   TargetTransformInfo::UnrollingPreferences UP = gatherUnrollingPreferences(
       L, SE, TTI, BFI, PSI, OptLevel, ProvidedThreshold, ProvidedCount,
       ProvidedAllowPartial, ProvidedRuntime, ProvidedUpperBound,
-      ProvidedAllowPeeling, ProvidedAllowProfileBasedPeeling,
       ProvidedFullUnrollMaxCount);
+  TargetTransformInfo::PeelingPreferences PP = gatherPeelingPreferences(
+      L, SE, TTI, ProvidedAllowPeeling, ProvidedAllowProfileBasedPeeling);
 
   // Exit early if unrolling is disabled. For OptForSize, we pick the loop size
   // as threshold later on.
@@ -1142,7 +1155,7 @@ static LoopUnrollResult tryToUnrollLoop(
   bool UseUpperBound = false;
   bool IsCountSetExplicitly = computeUnrollCount(
       L, TTI, DT, LI, SE, EphValues, &ORE, TripCount, MaxTripCount, MaxOrZero,
-      TripMultiple, LoopSize, UP, UseUpperBound);
+      TripMultiple, LoopSize, UP, PP, UseUpperBound);
   if (!UP.Count)
     return LoopUnrollResult::Unmodified;
   // Unroll factor (Count) must be less or equal to TripCount.
@@ -1157,7 +1170,7 @@ static LoopUnrollResult tryToUnrollLoop(
   LoopUnrollResult UnrollResult = UnrollLoop(
       L,
       {UP.Count, TripCount, UP.Force, UP.Runtime, UP.AllowExpensiveTripCount,
-       UseUpperBound, MaxOrZero, TripMultiple, UP.PeelCount, UP.UnrollRemainder,
+       UseUpperBound, MaxOrZero, TripMultiple, PP.PeelCount, UP.UnrollRemainder,
        ForgetAllSCEV},
       LI, &SE, &DT, &AC, &TTI, &ORE, PreserveLCSSA, &RemainderLoop);
   if (UnrollResult == LoopUnrollResult::Unmodified)
@@ -1189,7 +1202,7 @@ static LoopUnrollResult tryToUnrollLoop(
   // If the loop was peeled, we already "used up" the profile information
   // we had, so we don't want to unroll or peel again.
   if (UnrollResult != LoopUnrollResult::FullyUnrolled &&
-      (IsCountSetExplicitly || (UP.PeelProfiledIterations && UP.PeelCount)))
+      (IsCountSetExplicitly || (PP.PeelProfiledIterations && PP.PeelCount)))
     L->setLoopAlreadyUnrolled();
 
   return UnrollResult;

lib/Transforms/Utils/LoopUnrollPeel.cpp

@@ -279,19 +279,20 @@ static unsigned countToEliminateCompares(Loop &L, unsigned MaxPeelCount,
 // Return the number of iterations we want to peel off.
 void llvm::computePeelCount(Loop *L, unsigned LoopSize,
                             TargetTransformInfo::UnrollingPreferences &UP,
+                            TargetTransformInfo::PeelingPreferences &PP,
                             unsigned &TripCount, ScalarEvolution &SE) {
   assert(LoopSize > 0 && "Zero loop size is not allowed!");
-  // Save the UP.PeelCount value set by the target in
-  // TTI.getUnrollingPreferences or by the flag -unroll-peel-count.
-  unsigned TargetPeelCount = UP.PeelCount;
-  UP.PeelCount = 0;
+  // Save the PP.PeelCount value set by the target in
+  // TTI.getPeelingPreferences or by the flag -unroll-peel-count.
+  unsigned TargetPeelCount = PP.PeelCount;
+  PP.PeelCount = 0;
   if (!canPeel(L))
     return;
 
   // Only try to peel innermost loops by default.
   // The constraint can be relaxed by the target in TTI.getUnrollingPreferences
   // or by the flag -unroll-allow-loop-nests-peeling.
-  if (!UP.AllowLoopNestsPeeling && !L->empty())
+  if (!PP.AllowLoopNestsPeeling && !L->empty())
     return;
 
   // If the user provided a peel count, use that.
@@ -299,13 +300,13 @@ void llvm::computePeelCount(Loop *L, unsigned LoopSize,
   if (UserPeelCount) {
     LLVM_DEBUG(dbgs() << "Force-peeling first " << UnrollForcePeelCount
                       << " iterations.\n");
-    UP.PeelCount = UnrollForcePeelCount;
-    UP.PeelProfiledIterations = true;
+    PP.PeelCount = UnrollForcePeelCount;
+    PP.PeelProfiledIterations = true;
     return;
   }
 
   // Skip peeling if it's disabled.
-  if (!UP.AllowPeeling)
+  if (!PP.AllowPeeling)
     return;
 
   unsigned AlreadyPeeled = 0;
@@ -354,8 +355,8 @@ void llvm::computePeelCount(Loop *L, unsigned LoopSize,
         LLVM_DEBUG(dbgs() << "Peel " << DesiredPeelCount
                           << " iteration(s) to turn"
                           << " some Phis into invariants.\n");
-        UP.PeelCount = DesiredPeelCount;
-        UP.PeelProfiledIterations = false;
+        PP.PeelCount = DesiredPeelCount;
+        PP.PeelProfiledIterations = false;
         return;
       }
     }
@@ -367,7 +368,7 @@ void llvm::computePeelCount(Loop *L, unsigned LoopSize,
     return;
 
   // Do not apply profile base peeling if it is disabled.
-  if (!UP.PeelProfiledIterations)
+  if (!PP.PeelProfiledIterations)
     return;
   // If we don't know the trip count, but have reason to believe the average
   // trip count is low, peeling should be beneficial, since we will usually
@@ -387,7 +388,7 @@ void llvm::computePeelCount(Loop *L, unsigned LoopSize,
           (LoopSize * (*PeelCount + 1) <= UP.Threshold)) {
         LLVM_DEBUG(dbgs() << "Peeling first " << *PeelCount
                           << " iterations.\n");
-        UP.PeelCount = *PeelCount;
+        PP.PeelCount = *PeelCount;
         return;
       }
       LLVM_DEBUG(dbgs() << "Requested peel count: " << *PeelCount << "\n");