1 //==- llvm/CodeGen/MachineMemOperand.h - MachineMemOperand class -*- C++ -*-==//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_CODEGEN_MACHINEMEMOPERAND_H
17 #define LLVM_CODEGEN_MACHINEMEMOPERAND_H
19 #include "llvm/ADT/PointerUnion.h"
20 #include "llvm/CodeGen/PseudoSourceValue.h"
21 #include "llvm/IR/Value.h" // PointerLikeTypeTraits<Value*>
22 #include "llvm/Support/DataTypes.h"
26 class FoldingSetNodeID;
30 /// MachinePointerInfo - This class contains a discriminated union of
31 /// information about pointers in memory operands, relating them back to LLVM IR
32 /// or to virtual locations (such as frame indices) that are exposed during
34 struct MachinePointerInfo {
35 /// V - This is the IR pointer value for the access, or it is null if unknown.
36 /// If this is null, then the access is to a pointer in the default address
38 PointerUnion<const Value *, const PseudoSourceValue *> V;
40 /// Offset - This is an offset from the base Value*.
43 explicit MachinePointerInfo(const Value *v = nullptr, int64_t offset = 0)
44 : V(v), Offset(offset) {}
46 explicit MachinePointerInfo(const PseudoSourceValue *v,
48 : V(v), Offset(offset) {}
50 MachinePointerInfo getWithOffset(int64_t O) const {
51 if (V.isNull()) return MachinePointerInfo();
52 if (V.is<const Value*>())
53 return MachinePointerInfo(V.get<const Value*>(), Offset+O);
54 return MachinePointerInfo(V.get<const PseudoSourceValue*>(), Offset+O);
57 /// getAddrSpace - Return the LLVM IR address space number that this pointer
59 unsigned getAddrSpace() const;
61 /// getConstantPool - Return a MachinePointerInfo record that refers to the
63 static MachinePointerInfo getConstantPool();
65 /// getFixedStack - Return a MachinePointerInfo record that refers to the
66 /// the specified FrameIndex.
67 static MachinePointerInfo getFixedStack(int FI, int64_t offset = 0);
69 /// getJumpTable - Return a MachinePointerInfo record that refers to a
71 static MachinePointerInfo getJumpTable();
73 /// getGOT - Return a MachinePointerInfo record that refers to a
75 static MachinePointerInfo getGOT();
77 /// getStack - stack pointer relative access.
78 static MachinePointerInfo getStack(int64_t Offset);
82 //===----------------------------------------------------------------------===//
83 /// MachineMemOperand - A description of a memory reference used in the backend.
84 /// Instead of holding a StoreInst or LoadInst, this class holds the address
85 /// Value of the reference along with a byte size and offset. This allows it
86 /// to describe lowered loads and stores. Also, the special PseudoSourceValue
87 /// objects can be used to represent loads and stores to memory locations
88 /// that aren't explicit in the regular LLVM IR.
90 class MachineMemOperand {
91 MachinePointerInfo PtrInfo;
94 const MDNode *TBAAInfo;
98 /// Flags values. These may be or'd together.
99 enum MemOperandFlags {
100 /// The memory access reads data.
102 /// The memory access writes data.
104 /// The memory access is volatile.
106 /// The memory access is non-temporal.
108 /// The memory access is invariant.
110 // Target hints allow target passes to annotate memory operations.
111 MOTargetStartBit = 5,
113 // This is the number of bits we need to represent flags.
117 /// MachineMemOperand - Construct an MachineMemOperand object with the
118 /// specified PtrInfo, flags, size, and base alignment.
119 MachineMemOperand(MachinePointerInfo PtrInfo, unsigned flags, uint64_t s,
120 unsigned base_alignment, const MDNode *TBAAInfo = nullptr,
121 const MDNode *Ranges = nullptr);
123 const MachinePointerInfo &getPointerInfo() const { return PtrInfo; }
125 /// getValue - Return the base address of the memory access. This may either
126 /// be a normal LLVM IR Value, or one of the special values used in CodeGen.
127 /// Special values are those obtained via
128 /// PseudoSourceValue::getFixedStack(int), PseudoSourceValue::getStack, and
129 /// other PseudoSourceValue member functions which return objects which stand
130 /// for frame/stack pointer relative references and other special references
131 /// which are not representable in the high-level IR.
132 const Value *getValue() const { return PtrInfo.V.dyn_cast<const Value*>(); }
134 const PseudoSourceValue *getPseudoValue() const {
135 return PtrInfo.V.dyn_cast<const PseudoSourceValue*>();
138 const void *getOpaqueValue() const { return PtrInfo.V.getOpaqueValue(); }
140 /// getFlags - Return the raw flags of the source value, \see MemOperandFlags.
141 unsigned int getFlags() const { return Flags & ((1 << MOMaxBits) - 1); }
143 /// Bitwise OR the current flags with the given flags.
144 void setFlags(unsigned f) { Flags |= (f & ((1 << MOMaxBits) - 1)); }
146 /// getOffset - For normal values, this is a byte offset added to the base
147 /// address. For PseudoSourceValue::FPRel values, this is the FrameIndex
149 int64_t getOffset() const { return PtrInfo.Offset; }
151 unsigned getAddrSpace() const { return PtrInfo.getAddrSpace(); }
153 /// getSize - Return the size in bytes of the memory reference.
154 uint64_t getSize() const { return Size; }
156 /// getAlignment - Return the minimum known alignment in bytes of the
157 /// actual memory reference.
158 uint64_t getAlignment() const;
160 /// getBaseAlignment - Return the minimum known alignment in bytes of the
161 /// base address, without the offset.
162 uint64_t getBaseAlignment() const { return (1u << (Flags >> MOMaxBits)) >> 1; }
164 /// getTBAAInfo - Return the TBAA tag for the memory reference.
165 const MDNode *getTBAAInfo() const { return TBAAInfo; }
167 /// getRanges - Return the range tag for the memory reference.
168 const MDNode *getRanges() const { return Ranges; }
170 bool isLoad() const { return Flags & MOLoad; }
171 bool isStore() const { return Flags & MOStore; }
172 bool isVolatile() const { return Flags & MOVolatile; }
173 bool isNonTemporal() const { return Flags & MONonTemporal; }
174 bool isInvariant() const { return Flags & MOInvariant; }
176 /// isUnordered - Returns true if this memory operation doesn't have any
177 /// ordering constraints other than normal aliasing. Volatile and atomic
178 /// memory operations can't be reordered.
180 /// Currently, we don't model the difference between volatile and atomic
181 /// operations. They should retain their ordering relative to all memory
183 bool isUnordered() const { return !isVolatile(); }
185 /// refineAlignment - Update this MachineMemOperand to reflect the alignment
186 /// of MMO, if it has a greater alignment. This must only be used when the
187 /// new alignment applies to all users of this MachineMemOperand.
188 void refineAlignment(const MachineMemOperand *MMO);
190 /// setValue - Change the SourceValue for this MachineMemOperand. This
191 /// should only be used when an object is being relocated and all references
192 /// to it are being updated.
193 void setValue(const Value *NewSV) { PtrInfo.V = NewSV; }
194 void setValue(const PseudoSourceValue *NewSV) { PtrInfo.V = NewSV; }
195 void setOffset(int64_t NewOffset) { PtrInfo.Offset = NewOffset; }
197 /// Profile - Gather unique data for the object.
199 void Profile(FoldingSetNodeID &ID) const;
202 raw_ostream &operator<<(raw_ostream &OS, const MachineMemOperand &MRO);
204 } // End llvm namespace