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