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/Support/DataTypes.h" 20 21 namespace llvm { 22 23 class Value; 24 class FoldingSetNodeID; 25 class raw_ostream; 26 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 30 /// codegen. 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 34 /// space. 35 const Value *V; 36 37 /// Offset - This is an offset from the base Value*. 38 int64_t Offset; 39 40 explicit MachinePointerInfo(const Value *v = 0, int64_t offset = 0) VMachinePointerInfo41 : V(v), Offset(offset) {} 42 getWithOffsetMachinePointerInfo43 MachinePointerInfo getWithOffset(int64_t O) const { 44 if (V == 0) return MachinePointerInfo(0, 0); 45 return MachinePointerInfo(V, Offset+O); 46 } 47 48 /// getAddrSpace - Return the LLVM IR address space number that this pointer 49 /// points into. 50 unsigned getAddrSpace() const; 51 52 /// getConstantPool - Return a MachinePointerInfo record that refers to the 53 /// constant pool. 54 static MachinePointerInfo getConstantPool(); 55 56 /// getFixedStack - Return a MachinePointerInfo record that refers to the 57 /// the specified FrameIndex. 58 static MachinePointerInfo getFixedStack(int FI, int64_t offset = 0); 59 60 /// getJumpTable - Return a MachinePointerInfo record that refers to a 61 /// jump table entry. 62 static MachinePointerInfo getJumpTable(); 63 64 /// getGOT - Return a MachinePointerInfo record that refers to a 65 /// GOT entry. 66 static MachinePointerInfo getGOT(); 67 68 /// getStack - stack pointer relative access. 69 static MachinePointerInfo getStack(int64_t Offset); 70 }; 71 72 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. 80 /// 81 class MachineMemOperand { 82 MachinePointerInfo PtrInfo; 83 uint64_t Size; 84 unsigned Flags; 85 const MDNode *TBAAInfo; 86 87 public: 88 /// Flags values. These may be or'd together. 89 enum MemOperandFlags { 90 /// The memory access reads data. 91 MOLoad = 1, 92 /// The memory access writes data. 93 MOStore = 2, 94 /// The memory access is volatile. 95 MOVolatile = 4, 96 /// The memory access is non-temporal. 97 MONonTemporal = 8, 98 // This is the number of bits we need to represent flags. 99 MOMaxBits = 4 100 }; 101 102 /// 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); 106 getPointerInfo()107 const MachinePointerInfo &getPointerInfo() const { return PtrInfo; } 108 109 /// 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. getValue()116 const Value *getValue() const { return PtrInfo.V; } 117 118 /// getFlags - Return the raw flags of the source value, \see MemOperandFlags. getFlags()119 unsigned int getFlags() const { return Flags & ((1 << MOMaxBits) - 1); } 120 121 /// getOffset - For normal values, this is a byte offset added to the base 122 /// address. For PseudoSourceValue::FPRel values, this is the FrameIndex 123 /// number. getOffset()124 int64_t getOffset() const { return PtrInfo.Offset; } 125 126 /// getSize - Return the size in bytes of the memory reference. getSize()127 uint64_t getSize() const { return Size; } 128 129 /// getAlignment - Return the minimum known alignment in bytes of the 130 /// actual memory reference. 131 uint64_t getAlignment() const; 132 133 /// getBaseAlignment - Return the minimum known alignment in bytes of the 134 /// base address, without the offset. getBaseAlignment()135 uint64_t getBaseAlignment() const { return (1u << (Flags >> MOMaxBits)) >> 1; } 136 137 /// getTBAAInfo - Return the TBAA tag for the memory reference. getTBAAInfo()138 const MDNode *getTBAAInfo() const { return TBAAInfo; } 139 isLoad()140 bool isLoad() const { return Flags & MOLoad; } isStore()141 bool isStore() const { return Flags & MOStore; } isVolatile()142 bool isVolatile() const { return Flags & MOVolatile; } isNonTemporal()143 bool isNonTemporal() const { return Flags & MONonTemporal; } 144 145 /// 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); 149 150 /// 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. setValue(const Value * NewSV)153 void setValue(const Value *NewSV) { PtrInfo.V = NewSV; } setOffset(int64_t NewOffset)154 void setOffset(int64_t NewOffset) { PtrInfo.Offset = NewOffset; } 155 156 /// Profile - Gather unique data for the object. 157 /// 158 void Profile(FoldingSetNodeID &ID) const; 159 }; 160 161 raw_ostream &operator<<(raw_ostream &OS, const MachineMemOperand &MRO); 162 163 } // End llvm namespace 164 165 #endif 166