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/System/DataTypes.h"
24 class FoldingSetNodeID;
27 /// MachinePointerInfo - This class contains a discriminated union of
28 /// information about pointers in memory operands, relating them back to LLVM IR
29 /// or to virtual locations (such as frame indices) that are exposed during
31 struct MachinePointerInfo {
32 /// V - This is the IR pointer value for the access, or it is null if unknown.
33 /// If this is null, then the access is to a pointer in the default address
37 /// Offset - This is an offset from the base Value*.
40 explicit MachinePointerInfo(const Value *v = 0, int64_t offset = 0)
41 : V(v), Offset(offset) {}
43 MachinePointerInfo getWithOffset(int64_t O) const {
44 if (V == 0) return MachinePointerInfo(0, 0);
45 return MachinePointerInfo(V, Offset+O);
48 /// getAddrSpace - Return the LLVM IR address space number that this pointer
50 unsigned getAddrSpace() const;
52 /// getConstantPool - Return a MachinePointerInfo record that refers to the
54 static MachinePointerInfo getConstantPool();
56 /// getFixedStack - Return a MachinePointerInfo record that refers to the
57 /// the specified FrameIndex.
58 static MachinePointerInfo getFixedStack(int FI, int64_t offset = 0);
60 /// getJumpTable - Return a MachinePointerInfo record that refers to a
62 static MachinePointerInfo getJumpTable();
64 /// getGOT - Return a MachinePointerInfo record that refers to a
66 static MachinePointerInfo getGOT();
68 /// getStack - stack pointer relative access.
69 static MachinePointerInfo getStack(int64_t Offset);
73 //===----------------------------------------------------------------------===//
74 /// MachineMemOperand - A description of a memory reference used in the backend.
75 /// Instead of holding a StoreInst or LoadInst, this class holds the address
76 /// Value of the reference along with a byte size and offset. This allows it
77 /// to describe lowered loads and stores. Also, the special PseudoSourceValue
78 /// objects can be used to represent loads and stores to memory locations
79 /// that aren't explicit in the regular LLVM IR.
81 class MachineMemOperand {
82 MachinePointerInfo PtrInfo;
85 const MDNode *TBAAInfo;
88 /// Flags values. These may be or'd together.
89 enum MemOperandFlags {
90 /// The memory access reads data.
92 /// The memory access writes data.
94 /// The memory access is volatile.
96 /// The memory access is non-temporal.
98 // This is the number of bits we need to represent flags.
102 /// MachineMemOperand - Construct an MachineMemOperand object with the
103 /// specified PtrInfo, flags, size, and base alignment.
104 MachineMemOperand(MachinePointerInfo PtrInfo, unsigned flags, uint64_t s,
105 unsigned base_alignment, const MDNode *TBAAInfo = 0);
107 const MachinePointerInfo &getPointerInfo() const { return PtrInfo; }
109 /// getValue - Return the base address of the memory access. This may either
110 /// be a normal LLVM IR Value, or one of the special values used in CodeGen.
111 /// Special values are those obtained via
112 /// PseudoSourceValue::getFixedStack(int), PseudoSourceValue::getStack, and
113 /// other PseudoSourceValue member functions which return objects which stand
114 /// for frame/stack pointer relative references and other special references
115 /// which are not representable in the high-level IR.
116 const Value *getValue() const { return PtrInfo.V; }
118 /// getFlags - Return the raw flags of the source value, \see MemOperandFlags.
119 unsigned int getFlags() const { return Flags & ((1 << MOMaxBits) - 1); }
121 /// getOffset - For normal values, this is a byte offset added to the base
122 /// address. For PseudoSourceValue::FPRel values, this is the FrameIndex
124 int64_t getOffset() const { return PtrInfo.Offset; }
126 /// getSize - Return the size in bytes of the memory reference.
127 uint64_t getSize() const { return Size; }
129 /// getAlignment - Return the minimum known alignment in bytes of the
130 /// actual memory reference.
131 uint64_t getAlignment() const;
133 /// getBaseAlignment - Return the minimum known alignment in bytes of the
134 /// base address, without the offset.
135 uint64_t getBaseAlignment() const { return (1u << (Flags >> MOMaxBits)) >> 1; }
137 /// getTBAAInfo - Return the TBAA tag for the memory reference.
138 const MDNode *getTBAAInfo() const { return TBAAInfo; }
140 bool isLoad() const { return Flags & MOLoad; }
141 bool isStore() const { return Flags & MOStore; }
142 bool isVolatile() const { return Flags & MOVolatile; }
143 bool isNonTemporal() const { return Flags & MONonTemporal; }
145 /// refineAlignment - Update this MachineMemOperand to reflect the alignment
146 /// of MMO, if it has a greater alignment. This must only be used when the
147 /// new alignment applies to all users of this MachineMemOperand.
148 void refineAlignment(const MachineMemOperand *MMO);
150 /// setValue - Change the SourceValue for this MachineMemOperand. This
151 /// should only be used when an object is being relocated and all references
152 /// to it are being updated.
153 void setValue(const Value *NewSV) { PtrInfo.V = NewSV; }
154 void setOffset(int64_t NewOffset) { PtrInfo.Offset = NewOffset; }
156 /// Profile - Gather unique data for the object.
158 void Profile(FoldingSetNodeID &ID) const;
161 raw_ostream &operator<<(raw_ostream &OS, const MachineMemOperand &MRO);
163 } // End llvm namespace