[TTI] NFC: Change getFPOpCost to return InstructionCost

[sdesmalen]

Summary

This patch migrates the TTI cost interfaces to return an InstructionCost.

See this patch for the introduction of the type: https://reviews.llvm.org/D91174
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2020-November/146408.html

[c-rhodes]

LGTM

llvm/include/llvm/Analysis/TargetTransformInfo.h

public:
   /// Return true if it is faster to check if a floating-point value is NaN
   /// (or not-NaN) versus a comparison against a constant FP zero value.
   /// Targets should override this if materializing a 0.0 for comparison is
   /// generally as cheap as checking for ordered/unordered.
   bool isFCmpOrdCheaperThanFCmpZero(Type *Ty) const;
 
   /// Return the expected cost of supporting the floating point operation
   /// of the specified type.
-  int getFPOpCost(Type *Ty) const;
+  InstructionCost getFPOpCost(Type *Ty) const;
 
   /// Return the expected cost of materializing for the given integer
   /// immediate of the specified type.
   int getIntImmCost(const APInt &Imm, Type *Ty, TargetCostKind CostKind) const;
 
   /// Return the expected cost of materialization for the given integer
   /// immediate of the specified type for a given instruction. The cost can be
   /// zero if the immediate can be folded into the specified instruction.
public:
   virtual bool allowsMisalignedMemoryAccesses(LLVMContext &Context,
                                               unsigned BitWidth,
                                               unsigned AddressSpace,
                                               Align Alignment,
                                               bool *Fast) = 0;
   virtual PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) = 0;
   virtual bool haveFastSqrt(Type *Ty) = 0;
   virtual bool isFCmpOrdCheaperThanFCmpZero(Type *Ty) = 0;
-  virtual int getFPOpCost(Type *Ty) = 0;
+  virtual InstructionCost getFPOpCost(Type *Ty) = 0;
   virtual int getIntImmCodeSizeCost(unsigned Opc, unsigned Idx,
                                     const APInt &Imm, Type *Ty) = 0;
   virtual int getIntImmCost(const APInt &Imm, Type *Ty,
                             TargetCostKind CostKind) = 0;
   virtual int getIntImmCostInst(unsigned Opc, unsigned Idx, const APInt &Imm,
                                 Type *Ty, TargetCostKind CostKind,
                                 Instruction *Inst = nullptr) = 0;
   virtual int getIntImmCostIntrin(Intrinsic::ID IID, unsigned Idx,
PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) override {
     return Impl.getPopcntSupport(IntTyWidthInBit);
   }
   bool haveFastSqrt(Type *Ty) override { return Impl.haveFastSqrt(Ty); }
 
   bool isFCmpOrdCheaperThanFCmpZero(Type *Ty) override {
     return Impl.isFCmpOrdCheaperThanFCmpZero(Ty);
   }
 
-  int getFPOpCost(Type *Ty) override { return Impl.getFPOpCost(Ty); }
+  InstructionCost getFPOpCost(Type *Ty) override {
+    return Impl.getFPOpCost(Ty);
+  }
 
   int getIntImmCodeSizeCost(unsigned Opc, unsigned Idx, const APInt &Imm,
                             Type *Ty) override {
     return Impl.getIntImmCodeSizeCost(Opc, Idx, Imm, Ty);
   }
   int getIntImmCost(const APInt &Imm, Type *Ty,
                     TargetCostKind CostKind) override {
     return Impl.getIntImmCost(Imm, Ty, CostKind);

llvm/include/llvm/Analysis/TargetTransformInfoImpl.h

public:
   TTI::PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) const {
     return TTI::PSK_Software;
   }
 
   bool haveFastSqrt(Type *Ty) const { return false; }
 
   bool isFCmpOrdCheaperThanFCmpZero(Type *Ty) const { return true; }
 
-  unsigned getFPOpCost(Type *Ty) const {
+  InstructionCost getFPOpCost(Type *Ty) const {
     return TargetTransformInfo::TCC_Basic;
   }
 
   int getIntImmCodeSizeCost(unsigned Opcode, unsigned Idx, const APInt &Imm,
                             Type *Ty) const {
     return 0;
   }
 

llvm/include/llvm/CodeGen/BasicTTIImpl.h

bool haveFastSqrt(Type *Ty) {
     return TLI->isTypeLegal(VT) &&
            TLI->isOperationLegalOrCustom(ISD::FSQRT, VT);
   }
 
   bool isFCmpOrdCheaperThanFCmpZero(Type *Ty) {
     return true;
   }
 
-  unsigned getFPOpCost(Type *Ty) {
+  InstructionCost getFPOpCost(Type *Ty) {
     // Check whether FADD is available, as a proxy for floating-point in
     // general.
     const TargetLoweringBase *TLI = getTLI();
     EVT VT = TLI->getValueType(DL, Ty);
     if (TLI->isOperationLegalOrCustomOrPromote(ISD::FADD, VT))
       return TargetTransformInfo::TCC_Basic;
     return TargetTransformInfo::TCC_Expensive;
   }

llvm/lib/Analysis/TargetTransformInfo.cpp

 bool TargetTransformInfo::haveFastSqrt(Type *Ty) const {
   return TTIImpl->haveFastSqrt(Ty);
 }
 
 bool TargetTransformInfo::isFCmpOrdCheaperThanFCmpZero(Type *Ty) const {
   return TTIImpl->isFCmpOrdCheaperThanFCmpZero(Ty);
 }
 
-int TargetTransformInfo::getFPOpCost(Type *Ty) const {
-  int Cost = TTIImpl->getFPOpCost(Ty);
+InstructionCost TargetTransformInfo::getFPOpCost(Type *Ty) const {
+  InstructionCost Cost = TTIImpl->getFPOpCost(Ty);
   assert(Cost >= 0 && "TTI should not produce negative costs!");
   return Cost;
 }
 
 int TargetTransformInfo::getIntImmCodeSizeCost(unsigned Opcode, unsigned Idx,
                                                const APInt &Imm,
                                                Type *Ty) const {
   int Cost = TTIImpl->getIntImmCodeSizeCost(Opcode, Idx, Imm, Ty);