1//==- llvm/CodeGen/MachineMemOperand.h - MachineMemOperand class -*- C++ -*-==//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file contains the declaration of the MachineMemOperand class, which is a
11// description of a memory reference. It is used to help track dependencies
12// in the backend.
13//
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_CODEGEN_MACHINEMEMOPERAND_H
17#define LLVM_CODEGEN_MACHINEMEMOPERAND_H
18
19#include "llvm/ADT/PointerUnion.h"
20#include "llvm/CodeGen/PseudoSourceValue.h"
21#include "llvm/IR/Metadata.h"
22#include "llvm/IR/Value.h"  // PointerLikeTypeTraits<Value*>
23#include "llvm/Support/DataTypes.h"
24
25namespace llvm {
26
27class FoldingSetNodeID;
28class MDNode;
29class raw_ostream;
30
31/// MachinePointerInfo - This class contains a discriminated union of
32/// information about pointers in memory operands, relating them back to LLVM IR
33/// or to virtual locations (such as frame indices) that are exposed during
34/// codegen.
35struct MachinePointerInfo {
36  /// V - This is the IR pointer value for the access, or it is null if unknown.
37  /// If this is null, then the access is to a pointer in the default address
38  /// space.
39  PointerUnion<const Value *, const PseudoSourceValue *> V;
40
41  /// Offset - This is an offset from the base Value*.
42  int64_t Offset;
43
44  explicit MachinePointerInfo(const Value *v = nullptr, int64_t offset = 0)
45    : V(v), Offset(offset) {}
46
47  explicit MachinePointerInfo(const PseudoSourceValue *v,
48                              int64_t offset = 0)
49    : V(v), Offset(offset) {}
50
51  MachinePointerInfo getWithOffset(int64_t O) const {
52    if (V.isNull()) return MachinePointerInfo();
53    if (V.is<const Value*>())
54      return MachinePointerInfo(V.get<const Value*>(), Offset+O);
55    return MachinePointerInfo(V.get<const PseudoSourceValue*>(), Offset+O);
56  }
57
58  /// getAddrSpace - Return the LLVM IR address space number that this pointer
59  /// points into.
60  unsigned getAddrSpace() const;
61
62  /// getConstantPool - Return a MachinePointerInfo record that refers to the
63  /// constant pool.
64  static MachinePointerInfo getConstantPool();
65
66  /// getFixedStack - Return a MachinePointerInfo record that refers to the
67  /// the specified FrameIndex.
68  static MachinePointerInfo getFixedStack(int FI, int64_t offset = 0);
69
70  /// getJumpTable - Return a MachinePointerInfo record that refers to a
71  /// jump table entry.
72  static MachinePointerInfo getJumpTable();
73
74  /// getGOT - Return a MachinePointerInfo record that refers to a
75  /// GOT entry.
76  static MachinePointerInfo getGOT();
77
78  /// getStack - stack pointer relative access.
79  static MachinePointerInfo getStack(int64_t Offset);
80};
81
82
83//===----------------------------------------------------------------------===//
84/// MachineMemOperand - A description of a memory reference used in the backend.
85/// Instead of holding a StoreInst or LoadInst, this class holds the address
86/// Value of the reference along with a byte size and offset. This allows it
87/// to describe lowered loads and stores. Also, the special PseudoSourceValue
88/// objects can be used to represent loads and stores to memory locations
89/// that aren't explicit in the regular LLVM IR.
90///
91class MachineMemOperand {
92  MachinePointerInfo PtrInfo;
93  uint64_t Size;
94  unsigned Flags;
95  AAMDNodes AAInfo;
96  const MDNode *Ranges;
97
98public:
99  /// Flags values. These may be or'd together.
100  enum MemOperandFlags {
101    /// The memory access reads data.
102    MOLoad = 1,
103    /// The memory access writes data.
104    MOStore = 2,
105    /// The memory access is volatile.
106    MOVolatile = 4,
107    /// The memory access is non-temporal.
108    MONonTemporal = 8,
109    /// The memory access is invariant.
110    MOInvariant = 16,
111    // Target hints allow target passes to annotate memory operations.
112    MOTargetStartBit = 5,
113    MOTargetNumBits = 3,
114    // This is the number of bits we need to represent flags.
115    MOMaxBits = 8
116  };
117
118  /// MachineMemOperand - Construct an MachineMemOperand object with the
119  /// specified PtrInfo, flags, size, and base alignment.
120  MachineMemOperand(MachinePointerInfo PtrInfo, unsigned flags, uint64_t s,
121                    unsigned base_alignment,
122                    const AAMDNodes &AAInfo = AAMDNodes(),
123                    const MDNode *Ranges = nullptr);
124
125  const MachinePointerInfo &getPointerInfo() const { return PtrInfo; }
126
127  /// getValue - Return the base address of the memory access. This may either
128  /// be a normal LLVM IR Value, or one of the special values used in CodeGen.
129  /// Special values are those obtained via
130  /// PseudoSourceValue::getFixedStack(int), PseudoSourceValue::getStack, and
131  /// other PseudoSourceValue member functions which return objects which stand
132  /// for frame/stack pointer relative references and other special references
133  /// which are not representable in the high-level IR.
134  const Value *getValue() const { return PtrInfo.V.dyn_cast<const Value*>(); }
135
136  const PseudoSourceValue *getPseudoValue() const {
137    return PtrInfo.V.dyn_cast<const PseudoSourceValue*>();
138  }
139
140  const void *getOpaqueValue() const { return PtrInfo.V.getOpaqueValue(); }
141
142  /// getFlags - Return the raw flags of the source value, \see MemOperandFlags.
143  unsigned int getFlags() const { return Flags & ((1 << MOMaxBits) - 1); }
144
145  /// Bitwise OR the current flags with the given flags.
146  void setFlags(unsigned f) { Flags |= (f & ((1 << MOMaxBits) - 1)); }
147
148  /// getOffset - For normal values, this is a byte offset added to the base
149  /// address. For PseudoSourceValue::FPRel values, this is the FrameIndex
150  /// number.
151  int64_t getOffset() const { return PtrInfo.Offset; }
152
153  unsigned getAddrSpace() const { return PtrInfo.getAddrSpace(); }
154
155  /// getSize - Return the size in bytes of the memory reference.
156  uint64_t getSize() const { return Size; }
157
158  /// getAlignment - Return the minimum known alignment in bytes of the
159  /// actual memory reference.
160  uint64_t getAlignment() const;
161
162  /// getBaseAlignment - Return the minimum known alignment in bytes of the
163  /// base address, without the offset.
164  uint64_t getBaseAlignment() const { return (1u << (Flags >> MOMaxBits)) >> 1; }
165
166  /// getAAInfo - Return the AA tags for the memory reference.
167  AAMDNodes getAAInfo() const { return AAInfo; }
168
169  /// getRanges - Return the range tag for the memory reference.
170  const MDNode *getRanges() const { return Ranges; }
171
172  bool isLoad() const { return Flags & MOLoad; }
173  bool isStore() const { return Flags & MOStore; }
174  bool isVolatile() const { return Flags & MOVolatile; }
175  bool isNonTemporal() const { return Flags & MONonTemporal; }
176  bool isInvariant() const { return Flags & MOInvariant; }
177
178  /// isUnordered - Returns true if this memory operation doesn't have any
179  /// ordering constraints other than normal aliasing. Volatile and atomic
180  /// memory operations can't be reordered.
181  ///
182  /// Currently, we don't model the difference between volatile and atomic
183  /// operations. They should retain their ordering relative to all memory
184  /// operations.
185  bool isUnordered() const { return !isVolatile(); }
186
187  /// refineAlignment - Update this MachineMemOperand to reflect the alignment
188  /// of MMO, if it has a greater alignment. This must only be used when the
189  /// new alignment applies to all users of this MachineMemOperand.
190  void refineAlignment(const MachineMemOperand *MMO);
191
192  /// setValue - Change the SourceValue for this MachineMemOperand. This
193  /// should only be used when an object is being relocated and all references
194  /// to it are being updated.
195  void setValue(const Value *NewSV) { PtrInfo.V = NewSV; }
196  void setValue(const PseudoSourceValue *NewSV) { PtrInfo.V = NewSV; }
197  void setOffset(int64_t NewOffset) { PtrInfo.Offset = NewOffset; }
198
199  /// Profile - Gather unique data for the object.
200  ///
201  void Profile(FoldingSetNodeID &ID) const;
202
203  friend bool operator==(const MachineMemOperand &LHS,
204                         const MachineMemOperand &RHS) {
205    return LHS.getValue() == RHS.getValue() &&
206           LHS.getPseudoValue() == RHS.getPseudoValue() &&
207           LHS.getSize() == RHS.getSize() &&
208           LHS.getOffset() == RHS.getOffset() &&
209           LHS.getFlags() == RHS.getFlags() &&
210           LHS.getAAInfo() == RHS.getAAInfo() &&
211           LHS.getRanges() == RHS.getRanges() &&
212           LHS.getAlignment() == RHS.getAlignment() &&
213           LHS.getAddrSpace() == RHS.getAddrSpace();
214  }
215
216  friend bool operator!=(const MachineMemOperand &LHS,
217                         const MachineMemOperand &RHS) {
218    return !(LHS == RHS);
219  }
220};
221
222raw_ostream &operator<<(raw_ostream &OS, const MachineMemOperand &MRO);
223
224} // End llvm namespace
225
226#endif
227