[LSR][TTI][PowerPC][SystemZ][X86] Add const-ness to TTI::isLSRCostLess. NFC

[eopXD]

Update code.

[Meinersbur]

LGTM.

Do you have commit access? Could you add "NFC" (Non-Functional Change) into the title before committing?

llvm/include/llvm/Analysis/TargetTransformInfo.h

public:
   /// If target returns true in LSRWithInstrQueries(), I may be valid.
   /// TODO: Handle pre/postinc as well.
   bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
                              bool HasBaseReg, int64_t Scale,
                              unsigned AddrSpace = 0,
                              Instruction *I = nullptr) const;
 
   /// Return true if LSR cost of C1 is lower than C1.
-  bool isLSRCostLess(TargetTransformInfo::LSRCost &C1,
-                     TargetTransformInfo::LSRCost &C2) const;
+  bool isLSRCostLess(const TargetTransformInfo::LSRCost &C1,
+                     const TargetTransformInfo::LSRCost &C2) const;
 
   /// Return true if LSR major cost is number of registers. Targets which
   /// implement their own isLSRCostLess and unset number of registers as major
   /// cost should return false, otherwise return true.
   bool isNumRegsMajorCostOfLSR() const;
 
   /// \returns true if LSR should not optimize a chain that includes \p I.
   bool isProfitableLSRChainElement(Instruction *I) const;
virtual Optional<Value *> simplifyDemandedVectorEltsIntrinsic(
       std::function<void(Instruction *, unsigned, APInt, APInt &)>
           SimplifyAndSetOp) = 0;
   virtual bool isLegalAddImmediate(int64_t Imm) = 0;
   virtual bool isLegalICmpImmediate(int64_t Imm) = 0;
   virtual bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV,
                                      int64_t BaseOffset, bool HasBaseReg,
                                      int64_t Scale, unsigned AddrSpace,
                                      Instruction *I) = 0;
-  virtual bool isLSRCostLess(TargetTransformInfo::LSRCost &C1,
-                             TargetTransformInfo::LSRCost &C2) = 0;
+  virtual bool isLSRCostLess(const TargetTransformInfo::LSRCost &C1,
+                             const TargetTransformInfo::LSRCost &C2) = 0;
   virtual bool isNumRegsMajorCostOfLSR() = 0;
   virtual bool isProfitableLSRChainElement(Instruction *I) = 0;
   virtual bool canMacroFuseCmp() = 0;
   virtual bool canSaveCmp(Loop *L, BranchInst **BI, ScalarEvolution *SE,
                           LoopInfo *LI, DominatorTree *DT, AssumptionCache *AC,
                           TargetLibraryInfo *LibInfo) = 0;
   virtual AddressingModeKind
     getPreferredAddressingMode(const Loop *L, ScalarEvolution *SE) const = 0;
bool isLegalICmpImmediate(int64_t Imm) override {
     return Impl.isLegalICmpImmediate(Imm);
   }
   bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
                              bool HasBaseReg, int64_t Scale, unsigned AddrSpace,
                              Instruction *I) override {
     return Impl.isLegalAddressingMode(Ty, BaseGV, BaseOffset, HasBaseReg, Scale,
                                       AddrSpace, I);
   }
-  bool isLSRCostLess(TargetTransformInfo::LSRCost &C1,
-                     TargetTransformInfo::LSRCost &C2) override {
+  bool isLSRCostLess(const TargetTransformInfo::LSRCost &C1,
+                     const TargetTransformInfo::LSRCost &C2) override {
     return Impl.isLSRCostLess(C1, C2);
   }
   bool isNumRegsMajorCostOfLSR() override {
     return Impl.isNumRegsMajorCostOfLSR();
   }
   bool isProfitableLSRChainElement(Instruction *I) override {
     return Impl.isProfitableLSRChainElement(I);
   }

llvm/include/llvm/Analysis/TargetTransformInfoImpl.h

public:
   bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
                              bool HasBaseReg, int64_t Scale, unsigned AddrSpace,
                              Instruction *I = nullptr) const {
     // Guess that only reg and reg+reg addressing is allowed. This heuristic is
     // taken from the implementation of LSR.
     return !BaseGV && BaseOffset == 0 && (Scale == 0 || Scale == 1);
   }
 
-  bool isLSRCostLess(TTI::LSRCost &C1, TTI::LSRCost &C2) const {
+  bool isLSRCostLess(const TTI::LSRCost &C1, const TTI::LSRCost &C2) const {
     return std::tie(C1.NumRegs, C1.AddRecCost, C1.NumIVMuls, C1.NumBaseAdds,
                     C1.ScaleCost, C1.ImmCost, C1.SetupCost) <
            std::tie(C2.NumRegs, C2.AddRecCost, C2.NumIVMuls, C2.NumBaseAdds,
                     C2.ScaleCost, C2.ImmCost, C2.SetupCost);
   }
 
   bool isNumRegsMajorCostOfLSR() const { return true; }
 

llvm/lib/Analysis/TargetTransformInfo.cpp

bool TargetTransformInfo::isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV,
                                                 int64_t BaseOffset,
                                                 bool HasBaseReg, int64_t Scale,
                                                 unsigned AddrSpace,
                                                 Instruction *I) const {
   return TTIImpl->isLegalAddressingMode(Ty, BaseGV, BaseOffset, HasBaseReg,
                                         Scale, AddrSpace, I);
 }
 
-bool TargetTransformInfo::isLSRCostLess(LSRCost &C1, LSRCost &C2) const {
+bool TargetTransformInfo::isLSRCostLess(const LSRCost &C1,
+                                        const LSRCost &C2) const {
   return TTIImpl->isLSRCostLess(C1, C2);
 }
 
 bool TargetTransformInfo::isNumRegsMajorCostOfLSR() const {
   return TTIImpl->isNumRegsMajorCostOfLSR();
 }
 
 bool TargetTransformInfo::isProfitableLSRChainElement(Instruction *I) const {

llvm/lib/Target/PowerPC/PPCTargetTransformInfo.h

bool canSaveCmp(Loop *L, BranchInst **BI, ScalarEvolution *SE, LoopInfo *LI,
                   DominatorTree *DT, AssumptionCache *AC,
                   TargetLibraryInfo *LibInfo);
   bool getTgtMemIntrinsic(IntrinsicInst *Inst, MemIntrinsicInfo &Info);
   void getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                TTI::UnrollingPreferences &UP,
                                OptimizationRemarkEmitter *ORE);
   void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
                              TTI::PeelingPreferences &PP);
-  bool isLSRCostLess(TargetTransformInfo::LSRCost &C1,
-                     TargetTransformInfo::LSRCost &C2);
+  bool isLSRCostLess(const TargetTransformInfo::LSRCost &C1,
+                     const TargetTransformInfo::LSRCost &C2);
   bool isNumRegsMajorCostOfLSR();
   bool shouldBuildRelLookupTables() const;
   /// @}
 
   /// \name Vector TTI Implementations
   /// @{
   bool useColdCCForColdCall(Function &F);
   bool enableAggressiveInterleaving(bool LoopHasReductions);

llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp

bool PPCTTIImpl::canSaveCmp(Loop *L, BranchInst **BI, ScalarEvolution *SE,
 
   if (!HWLoopInfo.isHardwareLoopCandidate(*SE, *LI, *DT))
     return false;
 
   *BI = HWLoopInfo.ExitBranch;
   return true;
 }
 
-bool PPCTTIImpl::isLSRCostLess(TargetTransformInfo::LSRCost &C1,
-                               TargetTransformInfo::LSRCost &C2) {
+bool PPCTTIImpl::isLSRCostLess(const TargetTransformInfo::LSRCost &C1,
+                               const TargetTransformInfo::LSRCost &C2) {
   // PowerPC default behaviour here is "instruction number 1st priority".
   // If LsrNoInsnsCost is set, call default implementation.
   if (!LsrNoInsnsCost)
     return std::tie(C1.Insns, C1.NumRegs, C1.AddRecCost, C1.NumIVMuls,
                     C1.NumBaseAdds, C1.ScaleCost, C1.ImmCost, C1.SetupCost) <
            std::tie(C2.Insns, C2.NumRegs, C2.AddRecCost, C2.NumIVMuls,
                     C2.NumBaseAdds, C2.ScaleCost, C2.ImmCost, C2.SetupCost);
   else

llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.h

public:
 
   void getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                TTI::UnrollingPreferences &UP,
                                OptimizationRemarkEmitter *ORE);
 
   void getPeelingPreferences(Loop *L, ScalarEvolution &SE,
                              TTI::PeelingPreferences &PP);
 
-  bool isLSRCostLess(TargetTransformInfo::LSRCost &C1,
-                     TargetTransformInfo::LSRCost &C2);
+  bool isLSRCostLess(const TargetTransformInfo::LSRCost &C1,
+                     const TargetTransformInfo::LSRCost &C2);
   /// @}
 
   /// \name Vector TTI Implementations
   /// @{
 
   unsigned getNumberOfRegisters(unsigned ClassID) const;
   TypeSize getRegisterBitWidth(TargetTransformInfo::RegisterKind K) const;
 

llvm/lib/Target/SystemZ/SystemZTargetTransformInfo.cpp

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) {
+bool SystemZTTIImpl::isLSRCostLess(const TargetTransformInfo::LSRCost &C1,
+                                   const TargetTransformInfo::LSRCost &C2) {
   // SystemZ specific: check instruction count (first), and don't care about
   // ImmCost, since offsets are checked explicitly.
   return std::tie(C1.Insns, C1.NumRegs, C1.AddRecCost,
                   C1.NumIVMuls, C1.NumBaseAdds,
                   C1.ScaleCost, C1.SetupCost) <
     std::tie(C2.Insns, C2.NumRegs, C2.AddRecCost,
              C2.NumIVMuls, C2.NumBaseAdds,
              C2.ScaleCost, C2.SetupCost);

llvm/lib/Target/X86/X86TargetTransformInfo.h

public:
 
   InstructionCost getIntImmCostInst(unsigned Opcode, unsigned Idx,
                                     const APInt &Imm, Type *Ty,
                                     TTI::TargetCostKind CostKind,
                                     Instruction *Inst = nullptr);
   InstructionCost getIntImmCostIntrin(Intrinsic::ID IID, unsigned Idx,
                                       const APInt &Imm, Type *Ty,
                                       TTI::TargetCostKind CostKind);
-  bool isLSRCostLess(TargetTransformInfo::LSRCost &C1,
-                     TargetTransformInfo::LSRCost &C2);
+  bool isLSRCostLess(const TargetTransformInfo::LSRCost &C1,
+                     const TargetTransformInfo::LSRCost &C2);
   bool canMacroFuseCmp();
   bool isLegalMaskedLoad(Type *DataType, Align Alignment);
   bool isLegalMaskedStore(Type *DataType, Align Alignment);
   bool isLegalNTLoad(Type *DataType, Align Alignment);
   bool isLegalNTStore(Type *DataType, Align Alignment);
   bool isLegalBroadcastLoad(Type *ElementTy, ElementCount NumElements) const;
   bool forceScalarizeMaskedGather(VectorType *VTy, Align Alignment);
   bool forceScalarizeMaskedScatter(VectorType *VTy, Align Alignment) {

llvm/lib/Target/X86/X86TargetTransformInfo.cpp

if ((Opcode == Instruction::Load &&
         forceScalarizeMaskedScatter(cast<VectorType>(SrcVTy),
                                     Align(Alignment)))))
     return getGSScalarCost(Opcode, SrcVTy, VariableMask, Alignment,
                            AddressSpace);
 
   return getGSVectorCost(Opcode, SrcVTy, Ptr, Alignment, AddressSpace);
 }
 
-bool X86TTIImpl::isLSRCostLess(TargetTransformInfo::LSRCost &C1,
-                               TargetTransformInfo::LSRCost &C2) {
+bool X86TTIImpl::isLSRCostLess(const TargetTransformInfo::LSRCost &C1,
+                               const TargetTransformInfo::LSRCost &C2) {
     // X86 specific here are "instruction number 1st priority".
     return std::tie(C1.Insns, C1.NumRegs, C1.AddRecCost,
                     C1.NumIVMuls, C1.NumBaseAdds,
                     C1.ScaleCost, C1.ImmCost, C1.SetupCost) <
            std::tie(C2.Insns, C2.NumRegs, C2.AddRecCost,
                     C2.NumIVMuls, C2.NumBaseAdds,
                     C2.ScaleCost, C2.ImmCost, C2.SetupCost);
 }

llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp

Cost(const Loop *L, ScalarEvolution &SE, const TargetTransformInfo &TTI,
     C.AddRecCost = 0;
     C.NumIVMuls = 0;
     C.NumBaseAdds = 0;
     C.ImmCost = 0;
     C.SetupCost = 0;
     C.ScaleCost = 0;
   }
 
-  bool isLess(Cost &Other);
+  bool isLess(const Cost &Other);
 
   void Lose();
 
 #ifndef NDEBUG
   // Once any of the metrics loses, they must all remain losers.
   bool isValid() {
     return ((C.Insns | C.NumRegs | C.AddRecCost | C.NumIVMuls | C.NumBaseAdds
              | C.ImmCost | C.SetupCost | C.ScaleCost) != ~0u)
void Cost::Lose() {
   C.NumIVMuls = std::numeric_limits<unsigned>::max();
   C.NumBaseAdds = std::numeric_limits<unsigned>::max();
   C.ImmCost = std::numeric_limits<unsigned>::max();
   C.SetupCost = std::numeric_limits<unsigned>::max();
   C.ScaleCost = std::numeric_limits<unsigned>::max();
 }
 
 /// Choose the lower cost.
-bool Cost::isLess(Cost &Other) {
+bool Cost::isLess(const Cost &Other) {
   if (InsnsCost.getNumOccurrences() > 0 && InsnsCost &&
       C.Insns != Other.C.Insns)
     return C.Insns < Other.C.Insns;
   return TTI->isLSRCostLess(C, Other.C);
 }
 
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 void Cost::print(raw_ostream &OS) const {