Index: include/llvm/Analysis/TargetTransformInfo.h
===================================================================
--- include/llvm/Analysis/TargetTransformInfo.h
+++ include/llvm/Analysis/TargetTransformInfo.h
@@ -216,9 +216,23 @@
   /// other context they may not be folded. This routine can distinguish such
   /// cases.
   ///
+  /// To improve the estimation of the cost an optional list of operands can be
+  /// provided to be used instead of those the IR user currently uses.
+  /// The operands on the list can be a result of transformations of the current
+  /// operands. The number of the operands on the list must equal to the number
+  /// of the current operands the IR user has. Their order on the list must be
+  /// the same as the order of the current operands the IR user has.
+  ///
   /// The returned cost is defined in terms of \c TargetCostConstants, see its
   /// comments for a detailed explanation of the cost values.
-  int getUserCost(const User *U) const;
+  int getUserCost(const User *U, ArrayRef<const Value *> Operands) const;
+
+  /// \brief This is a helper function which calls the two-argument getUserCost
+  /// with an empty Operands list.
+  int getUserCost(const User *U) const {
+    ArrayRef<const Value *> Operands{};
+    return getUserCost(U, Operands);
+  }
 
   /// \brief Return true if branch divergence exists.
   ///
@@ -823,7 +837,8 @@
                                ArrayRef<const Value *> Arguments) = 0;
   virtual unsigned getEstimatedNumberOfCaseClusters(const SwitchInst &SI,
                                                     unsigned &JTSize) = 0;
-  virtual int getUserCost(const User *U) = 0;
+  virtual int getUserCost(const User *U,
+                          ArrayRef<const Value *> Operands) = 0;
   virtual bool hasBranchDivergence() = 0;
   virtual bool isSourceOfDivergence(const Value *V) = 0;
   virtual bool isAlwaysUniform(const Value *V) = 0;
@@ -998,7 +1013,10 @@
                        ArrayRef<const Value *> Arguments) override {
     return Impl.getIntrinsicCost(IID, RetTy, Arguments);
   }
-  int getUserCost(const User *U) override { return Impl.getUserCost(U); }
+  int getUserCost(const User *U,
+                  ArrayRef<const Value *> Operands) override {
+    return Impl.getUserCost(U, Operands);
+  }
   bool hasBranchDivergence() override { return Impl.hasBranchDivergence(); }
   bool isSourceOfDivergence(const Value *V) override {
     return Impl.isSourceOfDivergence(V);
Index: include/llvm/Analysis/TargetTransformInfoImpl.h
===================================================================
--- include/llvm/Analysis/TargetTransformInfoImpl.h
+++ include/llvm/Analysis/TargetTransformInfoImpl.h
@@ -684,12 +684,17 @@
     return static_cast<T *>(this)->getIntrinsicCost(IID, RetTy, ParamTys);
   }
 
-  unsigned getUserCost(const User *U) {
+  unsigned getUserCost(const User *U,
+                       ArrayRef<const Value *> Operands) {
     if (isa<PHINode>(U))
       return TTI::TCC_Free; // Model all PHI nodes as free.
 
     if (const GEPOperator *GEP = dyn_cast<GEPOperator>(U)) {
-      SmallVector<Value *, 4> Indices(GEP->idx_begin(), GEP->idx_end());
+      SmallVector<const Value *, 4> Indices;
+      if (!Operands.empty())
+        Indices.append(std::next(Operands.begin()), Operands.end());
+      else
+        Indices.append(GEP->idx_begin(), GEP->idx_end());
       return static_cast<T *>(this)->getGEPCost(
           GEP->getSourceElementType(), GEP->getPointerOperand(), Indices);
     }
Index: lib/Analysis/TargetTransformInfo.cpp
===================================================================
--- lib/Analysis/TargetTransformInfo.cpp
+++ lib/Analysis/TargetTransformInfo.cpp
@@ -89,8 +89,9 @@
   return TTIImpl->getEstimatedNumberOfCaseClusters(SI, JTSize);
 }
 
-int TargetTransformInfo::getUserCost(const User *U) const {
-  int Cost = TTIImpl->getUserCost(U);
+int TargetTransformInfo::getUserCost(
+    const User *U, ArrayRef<const Value *> Operands) const {
+  int Cost = TTIImpl->getUserCost(U, Operands);
   assert(Cost >= 0 && "TTI should not produce negative costs!");
   return Cost;
 }
Index: lib/Target/Hexagon/HexagonTargetTransformInfo.h
===================================================================
--- lib/Target/Hexagon/HexagonTargetTransformInfo.h
+++ lib/Target/Hexagon/HexagonTargetTransformInfo.h
@@ -61,7 +61,7 @@
 
   /// @}
 
-  int getUserCost(const User *U);
+  int getUserCost(const User *U, ArrayRef<const Value *> Operands);
 };
 
 } // end namespace llvm
Index: lib/Target/Hexagon/HexagonTargetTransformInfo.cpp
===================================================================
--- lib/Target/Hexagon/HexagonTargetTransformInfo.cpp
+++ lib/Target/Hexagon/HexagonTargetTransformInfo.cpp
@@ -46,8 +46,9 @@
   return getST()->getL1CacheLineSize();
 }
 
-int HexagonTTIImpl::getUserCost(const User *U) {
-  auto isCastFoldedIntoLoad = [] (const CastInst *CI) -> bool {
+int HexagonTTIImpl::getUserCost(const User *U,
+                                ArrayRef<const Value *> Operands) {
+  auto isCastFoldedIntoLoad = [](const CastInst *CI) -> bool {
     if (!CI->isIntegerCast())
       return false;
     const LoadInst *LI = dyn_cast<const LoadInst>(CI->getOperand(0));
@@ -67,5 +68,5 @@
   if (const CastInst *CI = dyn_cast<const CastInst>(U))
     if (isCastFoldedIntoLoad(CI))
       return TargetTransformInfo::TCC_Free;
-  return BaseT::getUserCost(U);
+  return BaseT::getUserCost(U, Operands);
 }