Revert r243347 "Add TargetTransformInfo::isZExtFree."

r243347 was intended to support a change to LSR (r243348).  That change
to LSR has since had to be reverted (r243939) because it was buggy, and
now the code added in r243347 is untested and unexercised.  Given that,
I think it is appropriate to revert r243347 for now, with the intent of
adding it back in later if I get around to checking in a fixed version
of r243348.

llvm-svn: 252948

llvm/include/llvm/Analysis/TargetTransformInfo.h

@@ -337,11 +337,6 @@ public:
   /// by referencing its sub-register AX.
   bool isTruncateFree(Type *Ty1, Type *Ty2) const;
 
-  /// \brief Return true if it's free to zero extend a value of type Ty1 to type
-  /// Ty2. e.g. on x86-64, all instructions that define 32-bit values implicit
-  /// zero-extend the result out to 64 bits.
-  bool isZExtFree(Type *Ty1, Type *Ty2) const;
-
   /// \brief Return true if it is profitable to hoist instruction in the
   /// then/else to before if.
   bool isProfitableToHoist(Instruction *I) const;
@@ -581,7 +576,6 @@ public:
                                    int64_t BaseOffset, bool HasBaseReg,
                                    int64_t Scale, unsigned AddrSpace) = 0;
   virtual bool isTruncateFree(Type *Ty1, Type *Ty2) = 0;
-  virtual bool isZExtFree(Type *Ty1, Type *Ty2) = 0;
   virtual bool isProfitableToHoist(Instruction *I) = 0;
   virtual bool isTypeLegal(Type *Ty) = 0;
   virtual unsigned getJumpBufAlignment() = 0;
@@ -721,9 +715,6 @@ public:
   bool isTruncateFree(Type *Ty1, Type *Ty2) override {
     return Impl.isTruncateFree(Ty1, Ty2);
   }
-  bool isZExtFree(Type *Ty1, Type *Ty2) override {
-    return Impl.isZExtFree(Ty1, Ty2);
-  }
   bool isProfitableToHoist(Instruction *I) override {
     return Impl.isProfitableToHoist(I);
   }

llvm/include/llvm/Analysis/TargetTransformInfoImpl.h

@@ -228,8 +228,6 @@ public:
 
   bool isTruncateFree(Type *Ty1, Type *Ty2) { return false; }
 
-  bool isZExtFree(Type *Ty1, Type *Ty2) { return false; }
-
   bool isProfitableToHoist(Instruction *I) { return true; }
 
   bool isTypeLegal(Type *Ty) { return false; }

llvm/include/llvm/CodeGen/BasicTTIImpl.h

@@ -143,10 +143,6 @@ public:
     return getTLI()->isTruncateFree(Ty1, Ty2);
   }
 
-  bool isZExtFree(Type *Ty1, Type *Ty2) const {
-    return getTLI()->isZExtFree(Ty1, Ty2);
-  }
-
   bool isProfitableToHoist(Instruction *I) {
     return getTLI()->isProfitableToHoist(I);
   }

llvm/lib/Analysis/TargetTransformInfo.cpp

@@ -144,10 +144,6 @@ bool TargetTransformInfo::isTruncateFree(Type *Ty1, Type *Ty2) const {
   return TTIImpl->isTruncateFree(Ty1, Ty2);
 }
 
-bool TargetTransformInfo::isZExtFree(Type *Ty1, Type *Ty2) const {
-  return TTIImpl->isZExtFree(Ty1, Ty2);
-}
-
 bool TargetTransformInfo::isProfitableToHoist(Instruction *I) const {
   return TTIImpl->isProfitableToHoist(I);
 }