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 MDNode; 26 class raw_ostream; 27 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 31 /// codegen. 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 35 /// space. 36 const Value *V; 37 38 /// Offset - This is an offset from the base Value*. 39 int64_t Offset; 40 41 explicit MachinePointerInfo(const Value *v = 0, int64_t offset = 0) 42 : V(v), Offset(offset) {} 43 44 MachinePointerInfo getWithOffset(int64_t O) const { 45 if (V == 0) return MachinePointerInfo(0, 0); 46 return MachinePointerInfo(V, Offset+O); 47 } 48 49 /// getAddrSpace - Return the LLVM IR address space number that this pointer 50 /// points into. 51 unsigned getAddrSpace() const; 52 53 /// getConstantPool - Return a MachinePointerInfo record that refers to the 54 /// constant pool. 55 static MachinePointerInfo getConstantPool(); 56 57 /// getFixedStack - Return a MachinePointerInfo record that refers to the 58 /// the specified FrameIndex. 59 static MachinePointerInfo getFixedStack(int FI, int64_t offset = 0); 60 61 /// getJumpTable - Return a MachinePointerInfo record that refers to a 62 /// jump table entry. 63 static MachinePointerInfo getJumpTable(); 64 65 /// getGOT - Return a MachinePointerInfo record that refers to a 66 /// GOT entry. 67 static MachinePointerInfo getGOT(); 68 69 /// getStack - stack pointer relative access. 70 static MachinePointerInfo getStack(int64_t Offset); 71 }; 72 73 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. 81 /// 82 class MachineMemOperand { 83 MachinePointerInfo PtrInfo; 84 uint64_t Size; 85 unsigned Flags; 86 const MDNode *TBAAInfo; 87 const MDNode *Ranges; 88 89 public: 90 /// Flags values. These may be or'd together. 91 enum MemOperandFlags { 92 /// The memory access reads data. 93 MOLoad = 1, 94 /// The memory access writes data. 95 MOStore = 2, 96 /// The memory access is volatile. 97 MOVolatile = 4, 98 /// The memory access is non-temporal. 99 MONonTemporal = 8, 100 /// The memory access is invariant. 101 MOInvariant = 16, 102 // Target hints allow target passes to annotate memory operations. 103 MOTargetStartBit = 5, 104 MOTargetNumBits = 3, 105 // This is the number of bits we need to represent flags. 106 MOMaxBits = 8 107 }; 108 109 /// MachineMemOperand - Construct an MachineMemOperand object with the 110 /// specified PtrInfo, flags, size, and base alignment. 111 MachineMemOperand(MachinePointerInfo PtrInfo, unsigned flags, uint64_t s, 112 unsigned base_alignment, const MDNode *TBAAInfo = 0, 113 const MDNode *Ranges = 0); 114 115 const MachinePointerInfo &getPointerInfo() const { return PtrInfo; } 116 117 /// getValue - Return the base address of the memory access. This may either 118 /// be a normal LLVM IR Value, or one of the special values used in CodeGen. 119 /// Special values are those obtained via 120 /// PseudoSourceValue::getFixedStack(int), PseudoSourceValue::getStack, and 121 /// other PseudoSourceValue member functions which return objects which stand 122 /// for frame/stack pointer relative references and other special references 123 /// which are not representable in the high-level IR. 124 const Value *getValue() const { return PtrInfo.V; } 125 126 /// getFlags - Return the raw flags of the source value, \see MemOperandFlags. 127 unsigned int getFlags() const { return Flags & ((1 << MOMaxBits) - 1); } 128 129 /// Bitwise OR the current flags with the given flags. 130 void setFlags(unsigned f) { Flags |= (f & ((1 << MOMaxBits) - 1)); } 131 132 /// getOffset - For normal values, this is a byte offset added to the base 133 /// address. For PseudoSourceValue::FPRel values, this is the FrameIndex 134 /// number. 135 int64_t getOffset() const { return PtrInfo.Offset; } 136 137 /// getSize - Return the size in bytes of the memory reference. 138 uint64_t getSize() const { return Size; } 139 140 /// getAlignment - Return the minimum known alignment in bytes of the 141 /// actual memory reference. 142 uint64_t getAlignment() const; 143 144 /// getBaseAlignment - Return the minimum known alignment in bytes of the 145 /// base address, without the offset. 146 uint64_t getBaseAlignment() const { return (1u << (Flags >> MOMaxBits)) >> 1; } 147 148 /// getTBAAInfo - Return the TBAA tag for the memory reference. 149 const MDNode *getTBAAInfo() const { return TBAAInfo; } 150 151 /// getRanges - Return the range tag for the memory reference. 152 const MDNode *getRanges() const { return Ranges; } 153 154 bool isLoad() const { return Flags & MOLoad; } 155 bool isStore() const { return Flags & MOStore; } 156 bool isVolatile() const { return Flags & MOVolatile; } 157 bool isNonTemporal() const { return Flags & MONonTemporal; } 158 bool isInvariant() const { return Flags & MOInvariant; } 159 160 /// isUnordered - Returns true if this memory operation doesn't have any 161 /// ordering constraints other than normal aliasing. Volatile and atomic 162 /// memory operations can't be reordered. 163 /// 164 /// Currently, we don't model the difference between volatile and atomic 165 /// operations. They should retain their ordering relative to all memory 166 /// operations. 167 bool isUnordered() const { return !isVolatile(); } 168 169 /// refineAlignment - Update this MachineMemOperand to reflect the alignment 170 /// of MMO, if it has a greater alignment. This must only be used when the 171 /// new alignment applies to all users of this MachineMemOperand. 172 void refineAlignment(const MachineMemOperand *MMO); 173 174 /// setValue - Change the SourceValue for this MachineMemOperand. This 175 /// should only be used when an object is being relocated and all references 176 /// to it are being updated. 177 void setValue(const Value *NewSV) { PtrInfo.V = NewSV; } 178 void setOffset(int64_t NewOffset) { PtrInfo.Offset = NewOffset; } 179 180 /// Profile - Gather unique data for the object. 181 /// 182 void Profile(FoldingSetNodeID &ID) const; 183 }; 184 185 raw_ostream &operator<<(raw_ostream &OS, const MachineMemOperand &MRO); 186 187 } // End llvm namespace 188 189 #endif 190
