1//===-- Address.h - An aligned address -------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This class provides a simple wrapper for a pair of a pointer and an
10// alignment.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_LIB_CODEGEN_ADDRESS_H
15#define LLVM_CLANG_LIB_CODEGEN_ADDRESS_H
16
17#include "llvm/IR/Constants.h"
18#include "clang/AST/CharUnits.h"
19
20namespace clang {
21namespace CodeGen {
22
23/// An aligned address.
24class Address {
25  llvm::Value *Pointer;
26  CharUnits Alignment;
27public:
28  Address(llvm::Value *pointer, CharUnits alignment)
29      : Pointer(pointer), Alignment(alignment) {
30    assert((!alignment.isZero() || pointer == nullptr) &&
31           "creating valid address with invalid alignment");
32  }
33
34  static Address invalid() { return Address(nullptr, CharUnits()); }
35  bool isValid() const { return Pointer != nullptr; }
36
37  llvm::Value *getPointer() const {
38    assert(isValid());
39    return Pointer;
40  }
41
42  /// Return the type of the pointer value.
43  llvm::PointerType *getType() const {
44    return llvm::cast<llvm::PointerType>(getPointer()->getType());
45  }
46
47  /// Return the type of the values stored in this address.
48  ///
49  /// When IR pointer types lose their element type, we should simply
50  /// store it in Address instead for the convenience of writing code.
51  llvm::Type *getElementType() const {
52    return getType()->getElementType();
53  }
54
55  /// Return the address space that this address resides in.
56  unsigned getAddressSpace() const {
57    return getType()->getAddressSpace();
58  }
59
60  /// Return the IR name of the pointer value.
61  llvm::StringRef getName() const {
62    return getPointer()->getName();
63  }
64
65  /// Return the alignment of this pointer.
66  CharUnits getAlignment() const {
67    assert(isValid());
68    return Alignment;
69  }
70};
71
72/// A specialization of Address that requires the address to be an
73/// LLVM Constant.
74class ConstantAddress : public Address {
75public:
76  ConstantAddress(llvm::Constant *pointer, CharUnits alignment)
77    : Address(pointer, alignment) {}
78
79  static ConstantAddress invalid() {
80    return ConstantAddress(nullptr, CharUnits());
81  }
82
83  llvm::Constant *getPointer() const {
84    return llvm::cast<llvm::Constant>(Address::getPointer());
85  }
86
87  ConstantAddress getBitCast(llvm::Type *ty) const {
88    return ConstantAddress(llvm::ConstantExpr::getBitCast(getPointer(), ty),
89                           getAlignment());
90  }
91
92  ConstantAddress getElementBitCast(llvm::Type *ty) const {
93    return getBitCast(ty->getPointerTo(getAddressSpace()));
94  }
95
96  static bool isaImpl(Address addr) {
97    return llvm::isa<llvm::Constant>(addr.getPointer());
98  }
99  static ConstantAddress castImpl(Address addr) {
100    return ConstantAddress(llvm::cast<llvm::Constant>(addr.getPointer()),
101                           addr.getAlignment());
102  }
103};
104
105}
106
107// Present a minimal LLVM-like casting interface.
108template <class U> inline U cast(CodeGen::Address addr) {
109  return U::castImpl(addr);
110}
111template <class U> inline bool isa(CodeGen::Address addr) {
112  return U::isaImpl(addr);
113}
114
115}
116
117#endif
118