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/Support/DataTypes.h"
24 class FoldingSetNodeID;
28 /// MachinePointerInfo - This class contains a discriminated union of
29 /// information about pointers in memory operands, relating them back to LLVM IR
30 /// or to virtual locations (such as frame indices) that are exposed during
32 struct MachinePointerInfo {
33 /// V - This is the IR pointer value for the access, or it is null if unknown.
34 /// If this is null, then the access is to a pointer in the default address
38 /// Offset - This is an offset from the base Value*.
41 explicit MachinePointerInfo(const Value *v = 0, int64_t offset = 0)
42 : V(v), Offset(offset) {}
44 MachinePointerInfo getWithOffset(int64_t O) const {
45 if (V == 0) return MachinePointerInfo(0, 0);
46 return MachinePointerInfo(V, Offset+O);
49 /// getAddrSpace - Return the LLVM IR address space number that this pointer
51 unsigned getAddrSpace() const;
53 /// getConstantPool - Return a MachinePointerInfo record that refers to the
55 static MachinePointerInfo getConstantPool();
57 /// getFixedStack - Return a MachinePointerInfo record that refers to the
58 /// the specified FrameIndex.
59 static MachinePointerInfo getFixedStack(int FI, int64_t offset = 0);
61 /// getJumpTable - Return a MachinePointerInfo record that refers to a
63 static MachinePointerInfo getJumpTable();
65 /// getGOT - Return a MachinePointerInfo record that refers to a
67 static MachinePointerInfo getGOT();
69 /// getStack - stack pointer relative access.
70 static MachinePointerInfo getStack(int64_t Offset);
74 //===----------------------------------------------------------------------===//
75 /// MachineMemOperand - A description of a memory reference used in the backend.
76 /// Instead of holding a StoreInst or LoadInst, this class holds the address
77 /// Value of the reference along with a byte size and offset. This allows it
78 /// to describe lowered loads and stores. Also, the special PseudoSourceValue
79 /// objects can be used to represent loads and stores to memory locations
80 /// that aren't explicit in the regular LLVM IR.
82 class MachineMemOperand {
83 MachinePointerInfo PtrInfo;
86 const MDNode *TBAAInfo;
90 /// Flags values. These may be or'd together.
91 enum MemOperandFlags {
92 /// The memory access reads data.
94 /// The memory access writes data.
96 /// The memory access is volatile.
98 /// The memory access is non-temporal.
100 /// The memory access is invariant.
102 // This is the number of bits we need to represent flags.
106 /// MachineMemOperand - Construct an MachineMemOperand object with the
107 /// specified PtrInfo, flags, size, and base alignment.
108 MachineMemOperand(MachinePointerInfo PtrInfo, unsigned flags, uint64_t s,
109 unsigned base_alignment, const MDNode *TBAAInfo = 0,
110 const MDNode *Ranges = 0);
112 const MachinePointerInfo &getPointerInfo() const { return PtrInfo; }
114 /// getValue - Return the base address of the memory access. This may either
115 /// be a normal LLVM IR Value, or one of the special values used in CodeGen.
116 /// Special values are those obtained via
117 /// PseudoSourceValue::getFixedStack(int), PseudoSourceValue::getStack, and
118 /// other PseudoSourceValue member functions which return objects which stand
119 /// for frame/stack pointer relative references and other special references
120 /// which are not representable in the high-level IR.
121 const Value *getValue() const { return PtrInfo.V; }
123 /// getFlags - Return the raw flags of the source value, \see MemOperandFlags.
124 unsigned int getFlags() const { return Flags & ((1 << MOMaxBits) - 1); }
126 /// getOffset - For normal values, this is a byte offset added to the base
127 /// address. For PseudoSourceValue::FPRel values, this is the FrameIndex
129 int64_t getOffset() const { return PtrInfo.Offset; }
131 /// getSize - Return the size in bytes of the memory reference.
132 uint64_t getSize() const { return Size; }
134 /// getAlignment - Return the minimum known alignment in bytes of the
135 /// actual memory reference.
136 uint64_t getAlignment() const;
138 /// getBaseAlignment - Return the minimum known alignment in bytes of the
139 /// base address, without the offset.
140 uint64_t getBaseAlignment() const { return (1u << (Flags >> MOMaxBits)) >> 1; }
142 /// getTBAAInfo - Return the TBAA tag for the memory reference.
143 const MDNode *getTBAAInfo() const { return TBAAInfo; }
145 /// getRanges - Return the range tag for the memory reference.
146 const MDNode *getRanges() const { return Ranges; }
148 bool isLoad() const { return Flags & MOLoad; }
149 bool isStore() const { return Flags & MOStore; }
150 bool isVolatile() const { return Flags & MOVolatile; }
151 bool isNonTemporal() const { return Flags & MONonTemporal; }
152 bool isInvariant() const { return Flags & MOInvariant; }
154 /// refineAlignment - Update this MachineMemOperand to reflect the alignment
155 /// of MMO, if it has a greater alignment. This must only be used when the
156 /// new alignment applies to all users of this MachineMemOperand.
157 void refineAlignment(const MachineMemOperand *MMO);
159 /// setValue - Change the SourceValue for this MachineMemOperand. This
160 /// should only be used when an object is being relocated and all references
161 /// to it are being updated.
162 void setValue(const Value *NewSV) { PtrInfo.V = NewSV; }
163 void setOffset(int64_t NewOffset) { PtrInfo.Offset = NewOffset; }
165 /// Profile - Gather unique data for the object.
167 void Profile(FoldingSetNodeID &ID) const;
170 raw_ostream &operator<<(raw_ostream &OS, const MachineMemOperand &MRO);
172 } // End llvm namespace