[DataLayout] Move '*AlignElem' structs and enum inside DataLayout (NFC) (#103723)

This makes `LayoutAlignElem` / `PointerAlignElem` and `AlignTypeEnum`
inner types of `DataLayout`. The types are also renamed to match their
meaning (LangRef refers to them as "specification" and "specifier").

Pull Request: #103723

Author: s-barannikov

llvm/include/llvm/IR/DataLayout.h

@@ -49,51 +49,11 @@ class StructLayout;
 class Triple;
 class Value;
 
-/// Enum used to categorize the alignment types stored by LayoutAlignElem
-enum AlignTypeEnum {
-  INTEGER_ALIGN = 'i',
-  VECTOR_ALIGN = 'v',
-  FLOAT_ALIGN = 'f',
-  AGGREGATE_ALIGN = 'a'
-};
-
 // FIXME: Currently the DataLayout string carries a "preferred alignment"
 // for types. As the DataLayout is module/global, this should likely be
 // sunk down to an FTTI element that is queried rather than a global
 // preference.
 
-/// Layout alignment element.
-///
-/// Stores the alignment data associated with a given type bit width.
-struct LayoutAlignElem {
-  uint32_t TypeBitWidth;
-  Align ABIAlign;
-  Align PrefAlign;
-
-  static LayoutAlignElem get(Align ABIAlign, Align PrefAlign,
-                             uint32_t BitWidth);
-
-  bool operator==(const LayoutAlignElem &rhs) const;
-};
-
-/// Layout pointer alignment element.
-///
-/// Stores the alignment data associated with a given pointer and address space.
-struct PointerAlignElem {
-  uint32_t AddressSpace;
-  uint32_t TypeBitWidth;
-  Align ABIAlign;
-  Align PrefAlign;
-  uint32_t IndexBitWidth;
-
-  /// Initializer
-  static PointerAlignElem getInBits(uint32_t AddressSpace, Align ABIAlign,
-                                    Align PrefAlign, uint32_t TypeBitWidth,
-                                    uint32_t IndexBitWidth);
-
-  bool operator==(const PointerAlignElem &rhs) const;
-};
-
 /// A parsed version of the target data layout string in and methods for
 /// querying it.
 ///
@@ -102,6 +62,26 @@ struct PointerAlignElem {
 /// target being codegen'd to.
 class DataLayout {
 public:
+  /// Primitive type specification.
+  struct PrimitiveSpec {
+    uint32_t BitWidth;
+    Align ABIAlign;
+    Align PrefAlign;
+
+    bool operator==(const PrimitiveSpec &Other) const;
+  };
+
+  /// Pointer type specification.
+  struct PointerSpec {
+    uint32_t AddrSpace;
+    uint32_t BitWidth;
+    Align ABIAlign;
+    Align PrefAlign;
+    uint32_t IndexBitWidth;
+
+    bool operator==(const PointerSpec &Other) const;
+  };
+
   enum class FunctionPtrAlignType {
     /// The function pointer alignment is independent of the function alignment.
     Independent,
@@ -135,20 +115,26 @@ class DataLayout {
   // FIXME: `unsigned char` truncates the value parsed by `parseSpecifier`.
   SmallVector<unsigned char, 8> LegalIntWidths;
 
-  // Primitive type specifications. Sorted and uniqued by type bit width.
-  SmallVector<LayoutAlignElem, 6> IntAlignments;
-  SmallVector<LayoutAlignElem, 4> FloatAlignments;
-  SmallVector<LayoutAlignElem, 10> VectorAlignments;
+  /// Type specifier used by some internal functions.
+  enum class TypeSpecifier {
+    Integer = 'i',
+    Float = 'f',
+    Vector = 'v',
+    Aggregate = 'a'
+  };
 
-  // Pointer type specifications. Sorted and uniqued by address space number.
-  SmallVector<PointerAlignElem, 8> Pointers;
+  /// Primitive type specifications. Sorted and uniqued by type bit width.
+  SmallVector<PrimitiveSpec, 6> IntSpecs;
+  SmallVector<PrimitiveSpec, 4> FloatSpecs;
+  SmallVector<PrimitiveSpec, 10> VectorSpecs;
+
+  /// Pointer type specifications. Sorted and uniqued by address space number.
+  SmallVector<PointerSpec, 8> PointerSpecs;
 
   /// The string representation used to create this DataLayout
   std::string StringRepresentation;
 
-  const PointerAlignElem &getPointerAlignElem(uint32_t AddressSpace) const;
-
-  // Struct type ABI and preferred alignments. The default spec is "a:8:64".
+  /// Struct type ABI and preferred alignments. The default spec is "a:8:64".
   Align StructABIAlignment = Align::Constant<1>();
   Align StructPrefAlignment = Align::Constant<8>();
 
@@ -159,16 +145,19 @@ class DataLayout {
   /// well-defined bitwise representation.
   SmallVector<unsigned, 8> NonIntegralAddressSpaces;
 
-  /// Attempts to set the alignment of the given type. Returns an error
-  /// description on failure.
-  Error setAlignment(AlignTypeEnum AlignType, Align ABIAlign, Align PrefAlign,
-                     uint32_t BitWidth);
+  /// Attempts to set the specification for the given type.
+  /// Returns an error description on failure.
+  Error setPrimitiveSpec(TypeSpecifier Specifier, uint32_t BitWidth,
+                         Align ABIAlign, Align PrefAlign);
+
+  /// Searches for a pointer specification that matches the given address space.
+  /// Returns the default address space specification if not found.
+  const PointerSpec &getPointerSpec(uint32_t AddrSpace) const;
 
-  /// Attempts to set the alignment of a pointer in the given address space.
+  /// Attempts to set the specification for pointer in the given address space.
   /// Returns an error description on failure.
-  Error setPointerAlignmentInBits(uint32_t AddrSpace, Align ABIAlign,
-                                  Align PrefAlign, uint32_t TypeBitWidth,
-                                  uint32_t IndexBitWidth);
+  Error setPointerSpec(uint32_t AddrSpace, uint32_t BitWidth, Align ABIAlign,
+                       Align PrefAlign, uint32_t IndexBitWidth);
 
   /// Internal helper to get alignment for integer of given bitwidth.
   Align getIntegerAlignment(uint32_t BitWidth, bool abi_or_pref) const;
@@ -375,7 +364,7 @@ class DataLayout {
   /// FIXME: The defaults need to be removed once all of
   /// the backends/clients are updated.
   unsigned getPointerSizeInBits(unsigned AS = 0) const {
-    return getPointerAlignElem(AS).TypeBitWidth;
+    return getPointerSpec(AS).BitWidth;
   }
 
   /// Returns the maximum index size over all address spaces.
@@ -385,7 +374,7 @@ class DataLayout {
 
   /// Size in bits of index used for address calculation in getelementptr.
   unsigned getIndexSizeInBits(unsigned AS) const {
-    return getPointerAlignElem(AS).IndexBitWidth;
+    return getPointerSpec(AS).IndexBitWidth;
   }
 
   /// Layout pointer size, in bits, based on the type.  If this function is