1 //===-- FunctionLoweringInfo.h - Lower functions from LLVM IR to CodeGen --===// 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 implements routines for translating functions from LLVM IR into 11 // Machine IR. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_CODEGEN_FUNCTIONLOWERINGINFO_H 16 #define LLVM_CODEGEN_FUNCTIONLOWERINGINFO_H 17 18 #include "llvm/InlineAsm.h" 19 #include "llvm/Instructions.h" 20 #include "llvm/ADT/APInt.h" 21 #include "llvm/ADT/DenseMap.h" 22 #include "llvm/ADT/DenseSet.h" 23 #include "llvm/ADT/IndexedMap.h" 24 #include "llvm/ADT/SmallPtrSet.h" 25 #include "llvm/ADT/SmallVector.h" 26 #include "llvm/Analysis/BranchProbabilityInfo.h" 27 #include "llvm/CodeGen/ValueTypes.h" 28 #include "llvm/CodeGen/ISDOpcodes.h" 29 #include "llvm/CodeGen/MachineBasicBlock.h" 30 #include "llvm/Support/CallSite.h" 31 #include "llvm/Target/TargetRegisterInfo.h" 32 #include <vector> 33 34 namespace llvm { 35 36 class AllocaInst; 37 class BasicBlock; 38 class CallInst; 39 class Function; 40 class GlobalVariable; 41 class Instruction; 42 class MachineInstr; 43 class MachineBasicBlock; 44 class MachineFunction; 45 class MachineModuleInfo; 46 class MachineRegisterInfo; 47 class TargetLowering; 48 class Value; 49 50 //===--------------------------------------------------------------------===// 51 /// FunctionLoweringInfo - This contains information that is global to a 52 /// function that is used when lowering a region of the function. 53 /// 54 class FunctionLoweringInfo { 55 public: 56 const TargetLowering &TLI; 57 const Function *Fn; 58 MachineFunction *MF; 59 MachineRegisterInfo *RegInfo; 60 BranchProbabilityInfo *BPI; 61 /// CanLowerReturn - true iff the function's return value can be lowered to 62 /// registers. 63 bool CanLowerReturn; 64 65 /// DemoteRegister - if CanLowerReturn is false, DemoteRegister is a vreg 66 /// allocated to hold a pointer to the hidden sret parameter. 67 unsigned DemoteRegister; 68 69 /// MBBMap - A mapping from LLVM basic blocks to their machine code entry. 70 DenseMap<const BasicBlock*, MachineBasicBlock *> MBBMap; 71 72 /// ValueMap - Since we emit code for the function a basic block at a time, 73 /// we must remember which virtual registers hold the values for 74 /// cross-basic-block values. 75 DenseMap<const Value*, unsigned> ValueMap; 76 77 /// StaticAllocaMap - Keep track of frame indices for fixed sized allocas in 78 /// the entry block. This allows the allocas to be efficiently referenced 79 /// anywhere in the function. 80 DenseMap<const AllocaInst*, int> StaticAllocaMap; 81 82 /// ByValArgFrameIndexMap - Keep track of frame indices for byval arguments. 83 DenseMap<const Argument*, int> ByValArgFrameIndexMap; 84 85 /// ArgDbgValues - A list of DBG_VALUE instructions created during isel for 86 /// function arguments that are inserted after scheduling is completed. 87 SmallVector<MachineInstr*, 8> ArgDbgValues; 88 89 /// RegFixups - Registers which need to be replaced after isel is done. 90 DenseMap<unsigned, unsigned> RegFixups; 91 92 /// MBB - The current block. 93 MachineBasicBlock *MBB; 94 95 /// MBB - The current insert position inside the current block. 96 MachineBasicBlock::iterator InsertPt; 97 98 #ifndef NDEBUG 99 SmallPtrSet<const Instruction *, 8> CatchInfoLost; 100 SmallPtrSet<const Instruction *, 8> CatchInfoFound; 101 #endif 102 103 struct LiveOutInfo { 104 unsigned NumSignBits : 31; 105 bool IsValid : 1; 106 APInt KnownOne, KnownZero; 107 LiveOutInfo() : NumSignBits(0), IsValid(true), KnownOne(1, 0), 108 KnownZero(1, 0) {} 109 }; 110 111 /// VisitedBBs - The set of basic blocks visited thus far by instruction 112 /// selection. 113 SmallPtrSet<const BasicBlock*, 4> VisitedBBs; 114 115 /// PHINodesToUpdate - A list of phi instructions whose operand list will 116 /// be updated after processing the current basic block. 117 /// TODO: This isn't per-function state, it's per-basic-block state. But 118 /// there's no other convenient place for it to live right now. 119 std::vector<std::pair<MachineInstr*, unsigned> > PHINodesToUpdate; 120 121 explicit FunctionLoweringInfo(const TargetLowering &TLI); 122 123 /// set - Initialize this FunctionLoweringInfo with the given Function 124 /// and its associated MachineFunction. 125 /// 126 void set(const Function &Fn, MachineFunction &MF); 127 128 /// clear - Clear out all the function-specific state. This returns this 129 /// FunctionLoweringInfo to an empty state, ready to be used for a 130 /// different function. 131 void clear(); 132 133 /// isExportedInst - Return true if the specified value is an instruction 134 /// exported from its block. 135 bool isExportedInst(const Value *V) { 136 return ValueMap.count(V); 137 } 138 139 unsigned CreateReg(EVT VT); 140 141 unsigned CreateRegs(Type *Ty); 142 143 unsigned InitializeRegForValue(const Value *V) { 144 unsigned &R = ValueMap[V]; 145 assert(R == 0 && "Already initialized this value register!"); 146 return R = CreateRegs(V->getType()); 147 } 148 149 /// GetLiveOutRegInfo - Gets LiveOutInfo for a register, returning NULL if the 150 /// register is a PHI destination and the PHI's LiveOutInfo is not valid. 151 const LiveOutInfo *GetLiveOutRegInfo(unsigned Reg) { 152 if (!LiveOutRegInfo.inBounds(Reg)) 153 return NULL; 154 155 const LiveOutInfo *LOI = &LiveOutRegInfo[Reg]; 156 if (!LOI->IsValid) 157 return NULL; 158 159 return LOI; 160 } 161 162 /// GetLiveOutRegInfo - Gets LiveOutInfo for a register, returning NULL if the 163 /// register is a PHI destination and the PHI's LiveOutInfo is not valid. If 164 /// the register's LiveOutInfo is for a smaller bit width, it is extended to 165 /// the larger bit width by zero extension. The bit width must be no smaller 166 /// than the LiveOutInfo's existing bit width. 167 const LiveOutInfo *GetLiveOutRegInfo(unsigned Reg, unsigned BitWidth); 168 169 /// AddLiveOutRegInfo - Adds LiveOutInfo for a register. 170 void AddLiveOutRegInfo(unsigned Reg, unsigned NumSignBits, 171 const APInt &KnownZero, const APInt &KnownOne) { 172 // Only install this information if it tells us something. 173 if (NumSignBits == 1 && KnownZero == 0 && KnownOne == 0) 174 return; 175 176 LiveOutRegInfo.grow(Reg); 177 LiveOutInfo &LOI = LiveOutRegInfo[Reg]; 178 LOI.NumSignBits = NumSignBits; 179 LOI.KnownOne = KnownOne; 180 LOI.KnownZero = KnownZero; 181 } 182 183 /// ComputePHILiveOutRegInfo - Compute LiveOutInfo for a PHI's destination 184 /// register based on the LiveOutInfo of its operands. 185 void ComputePHILiveOutRegInfo(const PHINode*); 186 187 /// InvalidatePHILiveOutRegInfo - Invalidates a PHI's LiveOutInfo, to be 188 /// called when a block is visited before all of its predecessors. 189 void InvalidatePHILiveOutRegInfo(const PHINode *PN) { 190 // PHIs with no uses have no ValueMap entry. 191 DenseMap<const Value*, unsigned>::const_iterator It = ValueMap.find(PN); 192 if (It == ValueMap.end()) 193 return; 194 195 unsigned Reg = It->second; 196 LiveOutRegInfo.grow(Reg); 197 LiveOutRegInfo[Reg].IsValid = false; 198 } 199 200 /// setArgumentFrameIndex - Record frame index for the byval 201 /// argument. 202 void setArgumentFrameIndex(const Argument *A, int FI); 203 204 /// getArgumentFrameIndex - Get frame index for the byval argument. 205 int getArgumentFrameIndex(const Argument *A); 206 207 private: 208 /// LiveOutRegInfo - Information about live out vregs. 209 IndexedMap<LiveOutInfo, VirtReg2IndexFunctor> LiveOutRegInfo; 210 }; 211 212 /// ComputeUsesVAFloatArgument - Determine if any floating-point values are 213 /// being passed to this variadic function, and set the MachineModuleInfo's 214 /// usesVAFloatArgument flag if so. This flag is used to emit an undefined 215 /// reference to _fltused on Windows, which will link in MSVCRT's 216 /// floating-point support. 217 void ComputeUsesVAFloatArgument(const CallInst &I, MachineModuleInfo *MMI); 218 219 /// AddCatchInfo - Extract the personality and type infos from an eh.selector 220 /// call, and add them to the specified machine basic block. 221 void AddCatchInfo(const CallInst &I, 222 MachineModuleInfo *MMI, MachineBasicBlock *MBB); 223 224 /// AddLandingPadInfo - Extract the exception handling information from the 225 /// landingpad instruction and add them to the specified machine module info. 226 void AddLandingPadInfo(const LandingPadInst &I, MachineModuleInfo &MMI, 227 MachineBasicBlock *MBB); 228 229 } // end namespace llvm 230 231 #endif 232
