[SVE] delete VectorType::getNumElements()

[ctetreau]

Summary

The previously agreed-upon deprecation period for
VectorType::getNumElements() has passed. This patch removes this method
and completes the refactor proposed in the RFC:
https://lists.llvm.org/pipermail/llvm-dev/2020-March/139811.html

[david-arm]

LGTM!

[rjmccall]

Thanks, I appreciate you following through with this. LGTM.

llvm/include/llvm/IR/DerivedTypes.h

 //===- llvm/DerivedTypes.h - Classes for handling data types ----*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
protected:
   const unsigned ElementQuantity;
 
   VectorType(Type *ElType, unsigned EQ, Type::TypeID TID);
 
 public:
   VectorType(const VectorType &) = delete;
   VectorType &operator=(const VectorType &) = delete;
 
-  /// Get the number of elements in this vector. It does not make sense to call
-  /// this function on a scalable vector, and this will be moved into
-  /// FixedVectorType in a future commit
-  LLVM_ATTRIBUTE_DEPRECATED(
-      inline unsigned getNumElements() const,
-      "Calling this function via a base VectorType is deprecated. Either call "
-      "getElementCount() and handle the case where Scalable is true or cast to "
-      "FixedVectorType.");
-
   Type *getElementType() const { return ContainedType; }
 
   /// This static method is the primary way to construct an VectorType.
   static VectorType *get(Type *ElementType, ElementCount EC);
 
   static VectorType *get(Type *ElementType, unsigned NumElements,
                          bool Scalable) {
     return VectorType::get(ElementType,
public:
 
   /// Methods for support type inquiry through isa, cast, and dyn_cast.
   static bool classof(const Type *T) {
     return T->getTypeID() == FixedVectorTyID ||
            T->getTypeID() == ScalableVectorTyID;
   }
 };
 
-unsigned VectorType::getNumElements() const {
-  ElementCount EC = getElementCount();
-#ifdef STRICT_FIXED_SIZE_VECTORS
-  assert(!EC.isScalable() &&
-         "Request for fixed number of elements from scalable vector");
-#else
-  if (EC.isScalable())
-    WithColor::warning()
-        << "The code that requested the fixed number of elements has made the "
-           "assumption that this vector is not scalable. This assumption was "
-           "not correct, and this may lead to broken code\n";
-#endif
-  return EC.getKnownMinValue();
-}
-
 /// Class to represent fixed width SIMD vectors
 class FixedVectorType : public VectorType {
 protected:
   FixedVectorType(Type *ElTy, unsigned NumElts)
       : VectorType(ElTy, NumElts, FixedVectorTyID) {}
 
 public:
   static FixedVectorType *get(Type *ElementType, unsigned NumElts);