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/Value.h" // PointerLikeTypeTraits<Value*> 22 #include "llvm/Support/DataTypes.h" 23 24 namespace llvm { 25 26 class FoldingSetNodeID; 27 class MDNode; 28 class raw_ostream; 29 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 33 /// codegen. 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 37 /// space. 38 PointerUnion<const Value *, const PseudoSourceValue *> V; 39 40 /// Offset - This is an offset from the base Value*. 41 int64_t Offset; 42 43 explicit MachinePointerInfo(const Value *v = nullptr, int64_t offset = 0) VMachinePointerInfo44 : V(v), Offset(offset) {} 45 46 explicit MachinePointerInfo(const PseudoSourceValue *v, 47 int64_t offset = 0) VMachinePointerInfo48 : V(v), Offset(offset) {} 49 getWithOffsetMachinePointerInfo50 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); 55 } 56 57 /// getAddrSpace - Return the LLVM IR address space number that this pointer 58 /// points into. 59 unsigned getAddrSpace() const; 60 61 /// getConstantPool - Return a MachinePointerInfo record that refers to the 62 /// constant pool. 63 static MachinePointerInfo getConstantPool(); 64 65 /// getFixedStack - Return a MachinePointerInfo record that refers to the 66 /// the specified FrameIndex. 67 static MachinePointerInfo getFixedStack(int FI, int64_t offset = 0); 68 69 /// getJumpTable - Return a MachinePointerInfo record that refers to a 70 /// jump table entry. 71 static MachinePointerInfo getJumpTable(); 72 73 /// getGOT - Return a MachinePointerInfo record that refers to a 74 /// GOT entry. 75 static MachinePointerInfo getGOT(); 76 77 /// getStack - stack pointer relative access. 78 static MachinePointerInfo getStack(int64_t Offset); 79 }; 80 81 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. 89 /// 90 class MachineMemOperand { 91 MachinePointerInfo PtrInfo; 92 uint64_t Size; 93 unsigned Flags; 94 const MDNode *TBAAInfo; 95 const MDNode *Ranges; 96 97 public: 98 /// Flags values. These may be or'd together. 99 enum MemOperandFlags { 100 /// The memory access reads data. 101 MOLoad = 1, 102 /// The memory access writes data. 103 MOStore = 2, 104 /// The memory access is volatile. 105 MOVolatile = 4, 106 /// The memory access is non-temporal. 107 MONonTemporal = 8, 108 /// The memory access is invariant. 109 MOInvariant = 16, 110 // Target hints allow target passes to annotate memory operations. 111 MOTargetStartBit = 5, 112 MOTargetNumBits = 3, 113 // This is the number of bits we need to represent flags. 114 MOMaxBits = 8 115 }; 116 117 /// 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); 122 getPointerInfo()123 const MachinePointerInfo &getPointerInfo() const { return PtrInfo; } 124 125 /// 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. getValue()132 const Value *getValue() const { return PtrInfo.V.dyn_cast<const Value*>(); } 133 getPseudoValue()134 const PseudoSourceValue *getPseudoValue() const { 135 return PtrInfo.V.dyn_cast<const PseudoSourceValue*>(); 136 } 137 getOpaqueValue()138 const void *getOpaqueValue() const { return PtrInfo.V.getOpaqueValue(); } 139 140 /// getFlags - Return the raw flags of the source value, \see MemOperandFlags. getFlags()141 unsigned int getFlags() const { return Flags & ((1 << MOMaxBits) - 1); } 142 143 /// Bitwise OR the current flags with the given flags. setFlags(unsigned f)144 void setFlags(unsigned f) { Flags |= (f & ((1 << MOMaxBits) - 1)); } 145 146 /// getOffset - For normal values, this is a byte offset added to the base 147 /// address. For PseudoSourceValue::FPRel values, this is the FrameIndex 148 /// number. getOffset()149 int64_t getOffset() const { return PtrInfo.Offset; } 150 getAddrSpace()151 unsigned getAddrSpace() const { return PtrInfo.getAddrSpace(); } 152 153 /// getSize - Return the size in bytes of the memory reference. getSize()154 uint64_t getSize() const { return Size; } 155 156 /// getAlignment - Return the minimum known alignment in bytes of the 157 /// actual memory reference. 158 uint64_t getAlignment() const; 159 160 /// getBaseAlignment - Return the minimum known alignment in bytes of the 161 /// base address, without the offset. getBaseAlignment()162 uint64_t getBaseAlignment() const { return (1u << (Flags >> MOMaxBits)) >> 1; } 163 164 /// getTBAAInfo - Return the TBAA tag for the memory reference. getTBAAInfo()165 const MDNode *getTBAAInfo() const { return TBAAInfo; } 166 167 /// getRanges - Return the range tag for the memory reference. getRanges()168 const MDNode *getRanges() const { return Ranges; } 169 isLoad()170 bool isLoad() const { return Flags & MOLoad; } isStore()171 bool isStore() const { return Flags & MOStore; } isVolatile()172 bool isVolatile() const { return Flags & MOVolatile; } isNonTemporal()173 bool isNonTemporal() const { return Flags & MONonTemporal; } isInvariant()174 bool isInvariant() const { return Flags & MOInvariant; } 175 176 /// 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. 179 /// 180 /// Currently, we don't model the difference between volatile and atomic 181 /// operations. They should retain their ordering relative to all memory 182 /// operations. isUnordered()183 bool isUnordered() const { return !isVolatile(); } 184 185 /// 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); 189 190 /// 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. setValue(const Value * NewSV)193 void setValue(const Value *NewSV) { PtrInfo.V = NewSV; } setValue(const PseudoSourceValue * NewSV)194 void setValue(const PseudoSourceValue *NewSV) { PtrInfo.V = NewSV; } setOffset(int64_t NewOffset)195 void setOffset(int64_t NewOffset) { PtrInfo.Offset = NewOffset; } 196 197 /// Profile - Gather unique data for the object. 198 /// 199 void Profile(FoldingSetNodeID &ID) const; 200 }; 201 202 raw_ostream &operator<<(raw_ostream &OS, const MachineMemOperand &MRO); 203 204 } // End llvm namespace 205 206 #endif 207