[TargetTransformInfo, API] Add a list of operands to TTI::getUserCost

The changes are a result of discussion of https://reviews.llvm.org/D33685.
It solves the following problem:

1. We can inform getGEPCost about simplified indices to help it with
   calculating the cost. But getGEPCost does not take into account the
   context which GEPs are used in.
2. We have getUserCost which can take the context into account but we cannot
   inform about simplified indices.

With the changes getUserCost will have access to additional information
as getGEPCost has.

The one parameter getUserCost is also provided.

Differential Revision: https://reviews.llvm.org/D34057

llvm-svn: 306674

5 files changed, 32 insertions, 13 deletions

diff --git a/llvm/include/llvm/Analysis/TargetTransformInfo.h b/llvm/include/llvm/Analysis/TargetTransformInfo.h
index f2a07006da4..68fbf640994 100644
--- a/llvm/include/llvm/Analysis/TargetTransformInfo.h
+++ b/llvm/include/llvm/Analysis/TargetTransformInfo.h
@@ -216,9 +216,23 @@ public:
   /// other context they may not be folded. This routine can distinguish such
   /// cases.
   ///
+  /// \p Operands is a list of operands which 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 \p Operands which are the current operands U has.
+  int getUserCost(const User *U) const {
+    SmallVector<const Value *, 4> Operands(U->value_op_begin(),
+                                           U->value_op_end());
+    return getUserCost(U, Operands);
+  }
 
   /// \brief Return true if branch divergence exists.
   ///
@@ -824,7 +838,8 @@ public:
                                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;
@@ -1000,7 +1015,9 @@ public:
                        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);
diff --git a/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h b/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
index defd9e73bc0..0246fc1c02c 100644
--- a/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
+++ b/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
@@ -685,14 +685,14 @@ public:
     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());
-      return static_cast<T *>(this)->getGEPCost(
-          GEP->getSourceElementType(), GEP->getPointerOperand(), Indices);
+      return static_cast<T *>(this)->getGEPCost(GEP->getSourceElementType(),
+                                                GEP->getPointerOperand(),
+                                                Operands.drop_front());
     }
 
     if (auto CS = ImmutableCallSite(U)) {
diff --git a/llvm/lib/Analysis/TargetTransformInfo.cpp b/llvm/lib/Analysis/TargetTransformInfo.cpp
index 91160954bd9..f938a9a5206 100644
--- a/llvm/lib/Analysis/TargetTransformInfo.cpp
+++ b/llvm/lib/Analysis/TargetTransformInfo.cpp
@@ -89,8 +89,9 @@ TargetTransformInfo::getEstimatedNumberOfCaseClusters(const SwitchInst &SI,
   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;
 }
diff --git a/llvm/lib/Target/Hexagon/HexagonTargetTransformInfo.cpp b/llvm/lib/Target/Hexagon/HexagonTargetTransformInfo.cpp
index d3848104d2b..4135d0cec70 100644
--- a/llvm/lib/Target/Hexagon/HexagonTargetTransformInfo.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonTargetTransformInfo.cpp
@@ -46,8 +46,9 @@ unsigned HexagonTTIImpl::getCacheLineSize() const {
   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 @@ int HexagonTTIImpl::getUserCost(const User *U) {
   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);
 }
diff --git a/llvm/lib/Target/Hexagon/HexagonTargetTransformInfo.h b/llvm/lib/Target/Hexagon/HexagonTargetTransformInfo.h
index 08faa2acd90..f08a2731057 100644
--- a/llvm/lib/Target/Hexagon/HexagonTargetTransformInfo.h
+++ b/llvm/lib/Target/Hexagon/HexagonTargetTransformInfo.h
@@ -62,7 +62,7 @@ public:
 
   /// @}
 
-  int getUserCost(const User *U);
+  int getUserCost(const User *U, ArrayRef<const Value *> Operands);
 };
 
 } // end namespace llvm