Ok, break down and add some cast<>'ing helper methods to the Type class

to reduce the number of cast<>'s we have.  This allows someone to use
things like Ty->getVectorNumElements() instead of 
cast<VectorType>(Ty)->getNumElements() when you know that a type is a
vector.

It would be a great general cleanup to move the codebase to use these,
I will do so in the code I'm touching.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148999 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Type.h

@@ -314,6 +314,32 @@ public:
   ///
   unsigned getNumContainedTypes() const { return NumContainedTys; }
 
+  //===--------------------------------------------------------------------===//
+  // Helper methods corresponding to subclass methods.  This forces a cast to
+  // the specified subclass and calls its accessor.  "getVectorNumElements" (for
+  // example) is shorthand for cast<VectorType>(Ty)->getNumElements().  This is
+  // only intended to cover the core methods that are frequently used, helper
+  // methods should not be added here.
+  
+  unsigned getIntegerBitWidth() const;
+
+  Type *getFunctionParamType(unsigned i) const;
+  unsigned getFunctionNumParams() const;
+  bool isFunctionVarArg() const;
+  
+  // TODO: StructType
+  
+  Type *getSequentialElementType() const;
+  
+  uint64_t getArrayNumElements() const;
+  Type *getArrayElementType() const { return getSequentialElementType(); }
+
+  unsigned getVectorNumElements() const;
+  Type *getVectorElementType() const { return getSequentialElementType(); }
+
+  unsigned getPointerAddressSpace() const;
+  Type *getPointerElementType() const { return getSequentialElementType(); }
+  
   //===--------------------------------------------------------------------===//
   // Static members exported by the Type class itself.  Useful for getting
   // instances of Type.

lib/VMCore/Type.cpp

@@ -197,6 +197,45 @@ bool Type::isSizedDerivedType() const {
   return true;
 }
 
+//===----------------------------------------------------------------------===//
+//                         Subclass Helper Methods
+//===----------------------------------------------------------------------===//
+
+unsigned Type::getIntegerBitWidth() const {
+  return cast<IntegerType>(this)->getBitWidth();
+}
+
+bool Type::isFunctionVarArg() const {
+  return cast<FunctionType>(this)->isVarArg();
+}
+
+Type *Type::getFunctionParamType(unsigned i) const {
+  return cast<FunctionType>(this)->getParamType(i);
+}
+
+unsigned Type::getFunctionNumParams() const {
+  return cast<FunctionType>(this)->getNumParams();
+}
+
+Type *Type::getSequentialElementType() const {
+  return cast<SequentialType>(this)->getElementType();
+}
+
+uint64_t Type::getArrayNumElements() const {
+  return cast<ArrayType>(this)->getNumElements();
+}
+
+unsigned Type::getVectorNumElements() const {
+  return cast<VectorType>(this)->getNumElements();
+}
+
+unsigned Type::getPointerAddressSpace() const {
+  return cast<PointerType>(this)->getAddressSpace();
+}
+
+
+
+
 //===----------------------------------------------------------------------===//
 //                          Primitive 'Type' data
 //===----------------------------------------------------------------------===//