[TTI] Expose isNoopAddrSpaceCast in TTI.

[hliao]

PING

llvm/include/llvm/Analysis/TargetTransformInfo.h

public:
 
   /// Return any intrinsic address operand indexes which may be rewritten if
   /// they use a flat address space pointer.
   ///
   /// \returns true if the intrinsic was handled.
   bool collectFlatAddressOperands(SmallVectorImpl<int> &OpIndexes,
                                   Intrinsic::ID IID) const;
 
+  bool isNoopAddrSpaceCast(unsigned FromAS, unsigned ToAS) const;
+
   /// Rewrite intrinsic call \p II such that \p OldV will be replaced with \p
   /// NewV, which has a different address space. This should happen for every
   /// operand index that collectFlatAddressOperands returned for the intrinsic.
   /// \returns nullptr if the intrinsic was not handled. Otherwise, returns the
   /// new value (which may be the original \p II with modified operands).
   Value *rewriteIntrinsicWithAddressSpace(IntrinsicInst *II, Value *OldV,
                                           Value *NewV) const;
 
virtual int getUserCost(const User *U, ArrayRef<const Value *> Operands,
                           TargetCostKind CostKind) = 0;
   virtual bool hasBranchDivergence() = 0;
   virtual bool useGPUDivergenceAnalysis() = 0;
   virtual bool isSourceOfDivergence(const Value *V) = 0;
   virtual bool isAlwaysUniform(const Value *V) = 0;
   virtual unsigned getFlatAddressSpace() = 0;
   virtual bool collectFlatAddressOperands(SmallVectorImpl<int> &OpIndexes,
                                           Intrinsic::ID IID) const = 0;
+  virtual bool isNoopAddrSpaceCast(unsigned FromAS, unsigned ToAS) const = 0;
   virtual Value *rewriteIntrinsicWithAddressSpace(IntrinsicInst *II,
                                                   Value *OldV,
                                                   Value *NewV) const = 0;
   virtual bool isLoweredToCall(const Function *F) = 0;
   virtual void getUnrollingPreferences(Loop *L, ScalarEvolution &,
                                        UnrollingPreferences &UP) = 0;
   virtual bool isHardwareLoopProfitable(Loop *L, ScalarEvolution &SE,
                                         AssumptionCache &AC,
public:
 
   unsigned getFlatAddressSpace() override { return Impl.getFlatAddressSpace(); }
 
   bool collectFlatAddressOperands(SmallVectorImpl<int> &OpIndexes,
                                   Intrinsic::ID IID) const override {
     return Impl.collectFlatAddressOperands(OpIndexes, IID);
   }
 
+  bool isNoopAddrSpaceCast(unsigned FromAS, unsigned ToAS) const override {
+    return Impl.isNoopAddrSpaceCast(FromAS, ToAS);
+  }
+
   Value *rewriteIntrinsicWithAddressSpace(IntrinsicInst *II, Value *OldV,
                                           Value *NewV) const override {
     return Impl.rewriteIntrinsicWithAddressSpace(II, OldV, NewV);
   }
 
   bool isLoweredToCall(const Function *F) override {
     return Impl.isLoweredToCall(F);
   }

llvm/include/llvm/Analysis/TargetTransformInfoImpl.h

public:
 
   unsigned getFlatAddressSpace() { return -1; }
 
   bool collectFlatAddressOperands(SmallVectorImpl<int> &OpIndexes,
                                   Intrinsic::ID IID) const {
     return false;
   }
 
+  bool isNoopAddrSpaceCast(unsigned, unsigned) const { return false; }
+
   Value *rewriteIntrinsicWithAddressSpace(IntrinsicInst *II, Value *OldV,
                                           Value *NewV) const {
     return nullptr;
   }
 
   bool isLoweredToCall(const Function *F) {
     assert(F && "A concrete function must be provided to this routine.");
 

llvm/include/llvm/CodeGen/BasicTTIImpl.h

unsigned getFlatAddressSpace() {
     return -1;
   }
 
   bool collectFlatAddressOperands(SmallVectorImpl<int> &OpIndexes,
                                   Intrinsic::ID IID) const {
     return false;
   }
 
+  bool isNoopAddrSpaceCast(unsigned FromAS, unsigned ToAS) const {
+    return getTLI()->isNoopAddrSpaceCast(FromAS, ToAS);
+  }
+
   Value *rewriteIntrinsicWithAddressSpace(IntrinsicInst *II, Value *OldV,
                                           Value *NewV) const {
     return nullptr;
   }
 
   bool isLegalAddImmediate(int64_t imm) {
     return getTLI()->isLegalAddImmediate(imm);
   }

llvm/lib/Analysis/TargetTransformInfo.cpp

unsigned TargetTransformInfo::getFlatAddressSpace() const {
   return TTIImpl->getFlatAddressSpace();
 }
 
 bool TargetTransformInfo::collectFlatAddressOperands(
     SmallVectorImpl<int> &OpIndexes, Intrinsic::ID IID) const {
   return TTIImpl->collectFlatAddressOperands(OpIndexes, IID);
 }
 
+bool TargetTransformInfo::isNoopAddrSpaceCast(unsigned FromAS,
+                                              unsigned ToAS) const {
+  return TTIImpl->isNoopAddrSpaceCast(FromAS, ToAS);
+}
+
 Value *TargetTransformInfo::rewriteIntrinsicWithAddressSpace(
     IntrinsicInst *II, Value *OldV, Value *NewV) const {
   return TTIImpl->rewriteIntrinsicWithAddressSpace(II, OldV, NewV);
 }
 
 bool TargetTransformInfo::isLoweredToCall(const Function *F) const {
   return TTIImpl->isLoweredToCall(F);
 }