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