[clang] [llvm] [WIP] ABI Lowering Library (PR #140112)

[Nikita Popov via llvm-commits]

================
@@ -0,0 +1,531 @@
+//===- ABI/Types.h ----------------------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file defines the Types and related helper methods concerned to the
+/// LLVMABI library which mirrors ABI related type information from
+/// the LLVM frontend.
+///
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_ABI_TYPES_H
+#define LLVM_ABI_TYPES_H
+
+#include "llvm/ADT/APFloat.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/Alignment.h"
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/TypeSize.h"
+#include <algorithm>
+#include <cstdint>
+
+namespace llvm {
+namespace abi {
+
+enum class TypeKind {
+  Void,
+  MemberPointer,
+  Complex,
+  Integer,
+  Float,
+  Pointer,
+  Array,
+  Vector,
+  Record,
+};
+
+class Type {
+private:
+  TypeSize getTypeStoreSize() const {
+    TypeSize StoreSizeInBits = getTypeStoreSizeInBits();
+    return {StoreSizeInBits.getKnownMinValue() / 8,
+            StoreSizeInBits.isScalable()};
+  }
+  TypeSize getTypeStoreSizeInBits() const {
+    TypeSize BaseSize = getSizeInBits();
+    uint64_t AlignedSizeInBits =
+        alignToPowerOf2(BaseSize.getKnownMinValue(), 8);
+    return {AlignedSizeInBits, BaseSize.isScalable()};
+  }
+
+protected:
+  TypeKind Kind;
+  TypeSize SizeInBits;
+  Align ABIAlignment;
+
+  Type(TypeKind K, TypeSize SizeInBits, Align ABIAlign)
+      : Kind(K), SizeInBits(SizeInBits), ABIAlignment(ABIAlign) {}
+
+public:
+  TypeKind getKind() const { return Kind; }
+  TypeSize getSizeInBits() const { return SizeInBits; }
+  Align getAlignment() const { return ABIAlignment; }
+
+  TypeSize getTypeAllocSize() const {
+    return alignTo(getTypeStoreSize(), getAlignment().value());
+  }
+
+  bool isVoid() const { return Kind == TypeKind::Void; }
+  bool isInteger() const { return Kind == TypeKind::Integer; }
+  bool isFloat() const { return Kind == TypeKind::Float; }
+  bool isPointer() const { return Kind == TypeKind::Pointer; }
+  bool isArray() const { return Kind == TypeKind::Array; }
+  bool isVector() const { return Kind == TypeKind::Vector; }
+  bool isRecord() const { return Kind == TypeKind::Record; }
+  bool isMemberPointer() const { return Kind == TypeKind::MemberPointer; }
+  bool isComplex() const { return Kind == TypeKind::Complex; }
+};
+
+class VoidType : public Type {
+public:
+  VoidType() : Type(TypeKind::Void, TypeSize::getFixed(0), Align(1)) {}
+
+  static bool classof(const Type *T) { return T->getKind() == TypeKind::Void; }
+};
+
+class ComplexType : public Type {
+public:
+  ComplexType(const Type *ElementType, uint64_t SizeInBits, Align Alignment)
+      : Type(TypeKind::Complex, TypeSize::getFixed(SizeInBits), Alignment),
+        ElementType(ElementType) {}
+
+  const Type *getElementType() const { return ElementType; }
+
+  static bool classof(const Type *T) {
+    return T->getKind() == TypeKind::Complex;
+  }
+
+private:
+  const Type *ElementType;
+};
+
+class IntegerType : public Type {
+private:
+  bool IsSigned;
+  bool IsBitInt;
+
+public:
+  IntegerType(uint64_t BitWidth, Align ABIAlign, bool IsSigned,
+              bool IsBitInt = false)
+      : Type(TypeKind::Integer, TypeSize::getFixed(BitWidth), ABIAlign),
+        IsSigned(IsSigned), IsBitInt(IsBitInt) {}
+
+  bool isSigned() const { return IsSigned; }
+  bool isBitInt() const { return IsBitInt; }
+  bool isBool() const {
+    return getSizeInBits().getFixedValue() == 1 && !IsBitInt;
+  }
+
+  static bool classof(const Type *T) {
+    return T->getKind() == TypeKind::Integer;
+  }
+};
+
+class FloatType : public Type {
+private:
+  const fltSemantics *Semantics;
+
+public:
+  FloatType(const fltSemantics &FloatSemantics, Align ABIAlign)
+      : Type(TypeKind::Float,
+             TypeSize::getFixed(APFloat::getSizeInBits(FloatSemantics)),
+             ABIAlign),
+        Semantics(&FloatSemantics) {}
+
+  const fltSemantics *getSemantics() const { return Semantics; }
+  static bool classof(const Type *T) { return T->getKind() == TypeKind::Float; }
+};
+
+class PointerLikeType : public Type {
+protected:
+  unsigned AddrSpace;
+  PointerLikeType(TypeKind K, TypeSize SizeInBits, Align ABIAlign, unsigned AS)
+      : Type(K, SizeInBits, ABIAlign), AddrSpace(AS) {}
+
+public:
+  unsigned getAddrSpace() const { return AddrSpace; }
+  bool isMemberPointer() const { return getKind() == TypeKind::MemberPointer; }
+
+  static bool classof(const Type *T) {
+    return T->getKind() == TypeKind::Pointer ||
+           T->getKind() == TypeKind::MemberPointer;
+  }
+};
+
+class PointerType : public PointerLikeType {
+public:
+  PointerType(uint64_t Size, Align ABIAlign, unsigned AddressSpace = 0)
+      : PointerLikeType(TypeKind::Pointer, TypeSize::getFixed(Size), ABIAlign,
+                        AddressSpace) {}
+
+  static bool classof(const Type *T) {
+    return T->getKind() == TypeKind::Pointer;
+  }
+};
+
+class MemberPointerType : public PointerLikeType {
+private:
+  bool IsFunctionPointer;
+
+public:
+  MemberPointerType(bool IsFunctionPointer, uint64_t SizeInBits, Align ABIAlign,
+                    unsigned AddressSpace = 0)
+      : PointerLikeType(TypeKind::MemberPointer, TypeSize::getFixed(SizeInBits),
+                        ABIAlign, AddressSpace),
+        IsFunctionPointer(IsFunctionPointer) {}
+  bool isFunctionPointer() const { return IsFunctionPointer; }
+
+  static bool classof(const Type *T) {
+    return T->getKind() == TypeKind::MemberPointer;
+  }
+};
+
+class ArrayType : public Type {
+private:
+  const Type *ElementType;
+  uint64_t NumElements;
+  bool IsMatrix;
+
+public:
+  ArrayType(const Type *ElementType, uint64_t NumElements, uint64_t SizeInBits,
+            bool IsMatrixType = false)
+      : Type(TypeKind::Array, TypeSize::getFixed(SizeInBits),
+             ElementType->getAlignment()),
+        ElementType(ElementType), NumElements(NumElements),
+        IsMatrix(IsMatrixType) {}
+
+  const Type *getElementType() const { return ElementType; }
+  uint64_t getNumElements() const { return NumElements; }
+  bool isMatrixType() const { return IsMatrix; }
+
+  static bool classof(const Type *T) { return T->getKind() == TypeKind::Array; }
+};
+
+class VectorType : public Type {
+private:
+  const Type *ElementType;
+  ElementCount NumElements;
+
+public:
+  VectorType(const Type *ElementType, ElementCount NumElements, Align ABIAlign)
+      : Type(TypeKind::Vector,
+             TypeSize(ElementType->getSizeInBits().getFixedValue() *
+                          NumElements.getKnownMinValue(),
+                      NumElements.isScalable()),
+             ABIAlign),
+        ElementType(ElementType), NumElements(NumElements) {}
+
+  const Type *getElementType() const { return ElementType; }
+  ElementCount getNumElements() const { return NumElements; }
+
+  static bool classof(const Type *T) {
+    return T->getKind() == TypeKind::Vector;
+  }
+};
+
+struct FieldInfo {
+  const Type *FieldType;
+  uint64_t OffsetInBits;
+  uint64_t BitFieldWidth;
+  bool IsBitField;
+  bool IsUnnamedBitfield;
+
+  FieldInfo(const Type *FieldType, uint64_t OffsetInBits = 0,
+            bool IsBitField = false, uint64_t BitFieldWidth = 0,
+            bool IsUnnamedBitField = false)
+      : FieldType(FieldType), OffsetInBits(OffsetInBits),
+        BitFieldWidth(BitFieldWidth), IsBitField(IsBitField),
+        IsUnnamedBitfield(IsUnnamedBitField) {}
+};
+
+enum class StructPacking { Default, Packed, ExplicitPacking };
+
+class RecordType : public Type {
+private:
+  ArrayRef<FieldInfo> Fields;
+  ArrayRef<FieldInfo> BaseClasses;
+  ArrayRef<FieldInfo> VirtualBaseClasses;
+  StructPacking Packing;
+  bool CanPassInRegisters;
+  bool IsCoercedRecord;
+  bool IsUnion;
+  bool IsTransparent;
----------------
nikic wrote:

You can use something like `LLVM_PREFERRED_TYPE(bool) unsigned IsTransparent : 1;` etc to pack these into bits.

https://github.com/llvm/llvm-project/pull/140112