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/Metadata.h"
22 #include "llvm/IR/Value.h" // PointerLikeTypeTraits<Value*>
23 #include "llvm/Support/DataTypes.h"
27 class FoldingSetNodeID;
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
35 struct 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
39 PointerUnion<const Value *, const PseudoSourceValue *> V;
41 /// Offset - This is an offset from the base Value*.
44 explicit MachinePointerInfo(const Value *v = nullptr, int64_t offset = 0)
45 : V(v), Offset(offset) {}
47 explicit MachinePointerInfo(const PseudoSourceValue *v,
49 : V(v), Offset(offset) {}
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);
58 /// getAddrSpace - Return the LLVM IR address space number that this pointer
60 unsigned getAddrSpace() const;
62 /// getConstantPool - Return a MachinePointerInfo record that refers to the
64 static MachinePointerInfo getConstantPool();
66 /// getFixedStack - Return a MachinePointerInfo record that refers to the
67 /// the specified FrameIndex.
68 static MachinePointerInfo getFixedStack(int FI, int64_t offset = 0);
70 /// getJumpTable - Return a MachinePointerInfo record that refers to a
72 static MachinePointerInfo getJumpTable();
74 /// getGOT - Return a MachinePointerInfo record that refers to a
76 static MachinePointerInfo getGOT();
78 /// getStack - stack pointer relative access.
79 static MachinePointerInfo getStack(int64_t Offset);
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.
91 class MachineMemOperand {
92 MachinePointerInfo PtrInfo;
99 /// Flags values. These may be or'd together.
100 enum MemOperandFlags {
101 /// The memory access reads data.
103 /// The memory access writes data.
105 /// The memory access is volatile.
107 /// The memory access is non-temporal.
109 /// The memory access is invariant.
111 // Target hints allow target passes to annotate memory operations.
112 MOTargetStartBit = 5,
114 // This is the number of bits we need to represent flags.
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);
125 const MachinePointerInfo &getPointerInfo() const { return PtrInfo; }
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*>(); }
136 const PseudoSourceValue *getPseudoValue() const {
137 return PtrInfo.V.dyn_cast<const PseudoSourceValue*>();
140 const void *getOpaqueValue() const { return PtrInfo.V.getOpaqueValue(); }
142 /// getFlags - Return the raw flags of the source value, \see MemOperandFlags.
143 unsigned int getFlags() const { return Flags & ((1 << MOMaxBits) - 1); }
145 /// Bitwise OR the current flags with the given flags.
146 void setFlags(unsigned f) { Flags |= (f & ((1 << MOMaxBits) - 1)); }
148 /// getOffset - For normal values, this is a byte offset added to the base
149 /// address. For PseudoSourceValue::FPRel values, this is the FrameIndex
151 int64_t getOffset() const { return PtrInfo.Offset; }
153 unsigned getAddrSpace() const { return PtrInfo.getAddrSpace(); }
155 /// getSize - Return the size in bytes of the memory reference.
156 uint64_t getSize() const { return Size; }
158 /// getAlignment - Return the minimum known alignment in bytes of the
159 /// actual memory reference.
160 uint64_t getAlignment() const;
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; }
166 /// getAAInfo - Return the AA tags for the memory reference.
167 AAMDNodes getAAInfo() const { return AAInfo; }
169 /// getRanges - Return the range tag for the memory reference.
170 const MDNode *getRanges() const { return Ranges; }
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; }
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.
182 /// Currently, we don't model the difference between volatile and atomic
183 /// operations. They should retain their ordering relative to all memory
185 bool isUnordered() const { return !isVolatile(); }
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);
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; }
199 /// Profile - Gather unique data for the object.
201 void Profile(FoldingSetNodeID &ID) const;
204 raw_ostream &operator<<(raw_ostream &OS, const MachineMemOperand &MRO);
206 } // End llvm namespace