X86InstrInfo.h revision a22edc82cab86be4cb8876da1e6e78f82bb47a3e
1//===- X86InstrInfo.h - X86 Instruction Information ------------*- 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 X86 implementation of the TargetInstrInfo class. 11// 12//===----------------------------------------------------------------------===// 13 14#ifndef X86INSTRUCTIONINFO_H 15#define X86INSTRUCTIONINFO_H 16 17#include "llvm/Target/TargetInstrInfo.h" 18#include "X86RegisterInfo.h" 19#include "llvm/ADT/IndexedMap.h" 20#include "llvm/Target/MRegisterInfo.h" 21 22namespace llvm { 23 class X86RegisterInfo; 24 class X86TargetMachine; 25 26namespace X86 { 27 // X86 specific condition code. These correspond to X86_*_COND in 28 // X86InstrInfo.td. They must be kept in synch. 29 enum CondCode { 30 COND_A = 0, 31 COND_AE = 1, 32 COND_B = 2, 33 COND_BE = 3, 34 COND_E = 4, 35 COND_G = 5, 36 COND_GE = 6, 37 COND_L = 7, 38 COND_LE = 8, 39 COND_NE = 9, 40 COND_NO = 10, 41 COND_NP = 11, 42 COND_NS = 12, 43 COND_O = 13, 44 COND_P = 14, 45 COND_S = 15, 46 COND_INVALID 47 }; 48 49 // Turn condition code into conditional branch opcode. 50 unsigned GetCondBranchFromCond(CondCode CC); 51 52 /// GetOppositeBranchCondition - Return the inverse of the specified cond, 53 /// e.g. turning COND_E to COND_NE. 54 CondCode GetOppositeBranchCondition(X86::CondCode CC); 55 56} 57 58/// X86II - This namespace holds all of the target specific flags that 59/// instruction info tracks. 60/// 61namespace X86II { 62 enum { 63 //===------------------------------------------------------------------===// 64 // Instruction types. These are the standard/most common forms for X86 65 // instructions. 66 // 67 68 // PseudoFrm - This represents an instruction that is a pseudo instruction 69 // or one that has not been implemented yet. It is illegal to code generate 70 // it, but tolerated for intermediate implementation stages. 71 Pseudo = 0, 72 73 /// Raw - This form is for instructions that don't have any operands, so 74 /// they are just a fixed opcode value, like 'leave'. 75 RawFrm = 1, 76 77 /// AddRegFrm - This form is used for instructions like 'push r32' that have 78 /// their one register operand added to their opcode. 79 AddRegFrm = 2, 80 81 /// MRMDestReg - This form is used for instructions that use the Mod/RM byte 82 /// to specify a destination, which in this case is a register. 83 /// 84 MRMDestReg = 3, 85 86 /// MRMDestMem - This form is used for instructions that use the Mod/RM byte 87 /// to specify a destination, which in this case is memory. 88 /// 89 MRMDestMem = 4, 90 91 /// MRMSrcReg - This form is used for instructions that use the Mod/RM byte 92 /// to specify a source, which in this case is a register. 93 /// 94 MRMSrcReg = 5, 95 96 /// MRMSrcMem - This form is used for instructions that use the Mod/RM byte 97 /// to specify a source, which in this case is memory. 98 /// 99 MRMSrcMem = 6, 100 101 /// MRM[0-7][rm] - These forms are used to represent instructions that use 102 /// a Mod/RM byte, and use the middle field to hold extended opcode 103 /// information. In the intel manual these are represented as /0, /1, ... 104 /// 105 106 // First, instructions that operate on a register r/m operand... 107 MRM0r = 16, MRM1r = 17, MRM2r = 18, MRM3r = 19, // Format /0 /1 /2 /3 108 MRM4r = 20, MRM5r = 21, MRM6r = 22, MRM7r = 23, // Format /4 /5 /6 /7 109 110 // Next, instructions that operate on a memory r/m operand... 111 MRM0m = 24, MRM1m = 25, MRM2m = 26, MRM3m = 27, // Format /0 /1 /2 /3 112 MRM4m = 28, MRM5m = 29, MRM6m = 30, MRM7m = 31, // Format /4 /5 /6 /7 113 114 // MRMInitReg - This form is used for instructions whose source and 115 // destinations are the same register. 116 MRMInitReg = 32, 117 118 FormMask = 63, 119 120 //===------------------------------------------------------------------===// 121 // Actual flags... 122 123 // OpSize - Set if this instruction requires an operand size prefix (0x66), 124 // which most often indicates that the instruction operates on 16 bit data 125 // instead of 32 bit data. 126 OpSize = 1 << 6, 127 128 // AsSize - Set if this instruction requires an operand size prefix (0x67), 129 // which most often indicates that the instruction address 16 bit address 130 // instead of 32 bit address (or 32 bit address in 64 bit mode). 131 AdSize = 1 << 7, 132 133 //===------------------------------------------------------------------===// 134 // Op0Mask - There are several prefix bytes that are used to form two byte 135 // opcodes. These are currently 0x0F, 0xF3, and 0xD8-0xDF. This mask is 136 // used to obtain the setting of this field. If no bits in this field is 137 // set, there is no prefix byte for obtaining a multibyte opcode. 138 // 139 Op0Shift = 8, 140 Op0Mask = 0xF << Op0Shift, 141 142 // TB - TwoByte - Set if this instruction has a two byte opcode, which 143 // starts with a 0x0F byte before the real opcode. 144 TB = 1 << Op0Shift, 145 146 // REP - The 0xF3 prefix byte indicating repetition of the following 147 // instruction. 148 REP = 2 << Op0Shift, 149 150 // D8-DF - These escape opcodes are used by the floating point unit. These 151 // values must remain sequential. 152 D8 = 3 << Op0Shift, D9 = 4 << Op0Shift, 153 DA = 5 << Op0Shift, DB = 6 << Op0Shift, 154 DC = 7 << Op0Shift, DD = 8 << Op0Shift, 155 DE = 9 << Op0Shift, DF = 10 << Op0Shift, 156 157 // XS, XD - These prefix codes are for single and double precision scalar 158 // floating point operations performed in the SSE registers. 159 XD = 11 << Op0Shift, XS = 12 << Op0Shift, 160 161 // T8, TA - Prefix after the 0x0F prefix. 162 T8 = 13 << Op0Shift, TA = 14 << Op0Shift, 163 164 //===------------------------------------------------------------------===// 165 // REX_W - REX prefixes are instruction prefixes used in 64-bit mode. 166 // They are used to specify GPRs and SSE registers, 64-bit operand size, 167 // etc. We only cares about REX.W and REX.R bits and only the former is 168 // statically determined. 169 // 170 REXShift = 12, 171 REX_W = 1 << REXShift, 172 173 //===------------------------------------------------------------------===// 174 // This three-bit field describes the size of an immediate operand. Zero is 175 // unused so that we can tell if we forgot to set a value. 176 ImmShift = 13, 177 ImmMask = 7 << ImmShift, 178 Imm8 = 1 << ImmShift, 179 Imm16 = 2 << ImmShift, 180 Imm32 = 3 << ImmShift, 181 Imm64 = 4 << ImmShift, 182 183 //===------------------------------------------------------------------===// 184 // FP Instruction Classification... Zero is non-fp instruction. 185 186 // FPTypeMask - Mask for all of the FP types... 187 FPTypeShift = 16, 188 FPTypeMask = 7 << FPTypeShift, 189 190 // NotFP - The default, set for instructions that do not use FP registers. 191 NotFP = 0 << FPTypeShift, 192 193 // ZeroArgFP - 0 arg FP instruction which implicitly pushes ST(0), f.e. fld0 194 ZeroArgFP = 1 << FPTypeShift, 195 196 // OneArgFP - 1 arg FP instructions which implicitly read ST(0), such as fst 197 OneArgFP = 2 << FPTypeShift, 198 199 // OneArgFPRW - 1 arg FP instruction which implicitly read ST(0) and write a 200 // result back to ST(0). For example, fcos, fsqrt, etc. 201 // 202 OneArgFPRW = 3 << FPTypeShift, 203 204 // TwoArgFP - 2 arg FP instructions which implicitly read ST(0), and an 205 // explicit argument, storing the result to either ST(0) or the implicit 206 // argument. For example: fadd, fsub, fmul, etc... 207 TwoArgFP = 4 << FPTypeShift, 208 209 // CompareFP - 2 arg FP instructions which implicitly read ST(0) and an 210 // explicit argument, but have no destination. Example: fucom, fucomi, ... 211 CompareFP = 5 << FPTypeShift, 212 213 // CondMovFP - "2 operand" floating point conditional move instructions. 214 CondMovFP = 6 << FPTypeShift, 215 216 // SpecialFP - Special instruction forms. Dispatch by opcode explicitly. 217 SpecialFP = 7 << FPTypeShift, 218 219 // Bits 19 -> 23 are unused 220 OpcodeShift = 24, 221 OpcodeMask = 0xFF << OpcodeShift 222 }; 223} 224 225class X86InstrInfo : public TargetInstrInfoImpl { 226 X86TargetMachine &TM; 227 const X86RegisterInfo RI; 228 229 /// RegOp2MemOpTable2Addr, RegOp2MemOpTable0, RegOp2MemOpTable1, 230 /// RegOp2MemOpTable2 - Load / store folding opcode maps. 231 /// 232 DenseMap<unsigned*, unsigned> RegOp2MemOpTable2Addr; 233 DenseMap<unsigned*, unsigned> RegOp2MemOpTable0; 234 DenseMap<unsigned*, unsigned> RegOp2MemOpTable1; 235 DenseMap<unsigned*, unsigned> RegOp2MemOpTable2; 236 237 /// MemOp2RegOpTable - Load / store unfolding opcode map. 238 /// 239 DenseMap<unsigned*, std::pair<unsigned, unsigned> > MemOp2RegOpTable; 240 241public: 242 X86InstrInfo(X86TargetMachine &tm); 243 244 /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info. As 245 /// such, whenever a client has an instance of instruction info, it should 246 /// always be able to get register info as well (through this method). 247 /// 248 virtual const MRegisterInfo &getRegisterInfo() const { return RI; } 249 250 // Return true if the instruction is a register to register move and 251 // leave the source and dest operands in the passed parameters. 252 // 253 bool isMoveInstr(const MachineInstr& MI, unsigned& sourceReg, 254 unsigned& destReg) const; 255 unsigned isLoadFromStackSlot(MachineInstr *MI, int &FrameIndex) const; 256 unsigned isStoreToStackSlot(MachineInstr *MI, int &FrameIndex) const; 257 bool isReallyTriviallyReMaterializable(MachineInstr *MI) const; 258 bool isInvariantLoad(MachineInstr *MI) const; 259 260 /// convertToThreeAddress - This method must be implemented by targets that 261 /// set the M_CONVERTIBLE_TO_3_ADDR flag. When this flag is set, the target 262 /// may be able to convert a two-address instruction into a true 263 /// three-address instruction on demand. This allows the X86 target (for 264 /// example) to convert ADD and SHL instructions into LEA instructions if they 265 /// would require register copies due to two-addressness. 266 /// 267 /// This method returns a null pointer if the transformation cannot be 268 /// performed, otherwise it returns the new instruction. 269 /// 270 virtual MachineInstr *convertToThreeAddress(MachineFunction::iterator &MFI, 271 MachineBasicBlock::iterator &MBBI, 272 LiveVariables &LV) const; 273 274 /// commuteInstruction - We have a few instructions that must be hacked on to 275 /// commute them. 276 /// 277 virtual MachineInstr *commuteInstruction(MachineInstr *MI) const; 278 279 // Branch analysis. 280 virtual bool isUnpredicatedTerminator(const MachineInstr* MI) const; 281 virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB, 282 MachineBasicBlock *&FBB, 283 std::vector<MachineOperand> &Cond) const; 284 virtual unsigned RemoveBranch(MachineBasicBlock &MBB) const; 285 virtual unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB, 286 MachineBasicBlock *FBB, 287 const std::vector<MachineOperand> &Cond) const; 288 virtual void copyRegToReg(MachineBasicBlock &MBB, 289 MachineBasicBlock::iterator MI, 290 unsigned DestReg, unsigned SrcReg, 291 const TargetRegisterClass *DestRC, 292 const TargetRegisterClass *SrcRC) const; 293 virtual void storeRegToStackSlot(MachineBasicBlock &MBB, 294 MachineBasicBlock::iterator MI, 295 unsigned SrcReg, bool isKill, int FrameIndex, 296 const TargetRegisterClass *RC) const; 297 298 virtual void storeRegToAddr(MachineFunction &MF, unsigned SrcReg, bool isKill, 299 SmallVectorImpl<MachineOperand> &Addr, 300 const TargetRegisterClass *RC, 301 SmallVectorImpl<MachineInstr*> &NewMIs) const; 302 303 virtual void loadRegFromStackSlot(MachineBasicBlock &MBB, 304 MachineBasicBlock::iterator MI, 305 unsigned DestReg, int FrameIndex, 306 const TargetRegisterClass *RC) const; 307 308 virtual void loadRegFromAddr(MachineFunction &MF, unsigned DestReg, 309 SmallVectorImpl<MachineOperand> &Addr, 310 const TargetRegisterClass *RC, 311 SmallVectorImpl<MachineInstr*> &NewMIs) const; 312 313 virtual bool spillCalleeSavedRegisters(MachineBasicBlock &MBB, 314 MachineBasicBlock::iterator MI, 315 const std::vector<CalleeSavedInfo> &CSI) const; 316 317 virtual bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB, 318 MachineBasicBlock::iterator MI, 319 const std::vector<CalleeSavedInfo> &CSI) const; 320 321 /// foldMemoryOperand - If this target supports it, fold a load or store of 322 /// the specified stack slot into the specified machine instruction for the 323 /// specified operand(s). If this is possible, the target should perform the 324 /// folding and return true, otherwise it should return false. If it folds 325 /// the instruction, it is likely that the MachineInstruction the iterator 326 /// references has been changed. 327 virtual MachineInstr* foldMemoryOperand(MachineInstr* MI, 328 SmallVectorImpl<unsigned> &Ops, 329 int FrameIndex) const; 330 331 /// foldMemoryOperand - Same as the previous version except it allows folding 332 /// of any load and store from / to any address, not just from a specific 333 /// stack slot. 334 virtual MachineInstr* foldMemoryOperand(MachineInstr* MI, 335 SmallVectorImpl<unsigned> &Ops, 336 MachineInstr* LoadMI) const; 337 338 /// canFoldMemoryOperand - Returns true if the specified load / store is 339 /// folding is possible. 340 virtual bool canFoldMemoryOperand(MachineInstr*, SmallVectorImpl<unsigned> &) const; 341 342 /// unfoldMemoryOperand - Separate a single instruction which folded a load or 343 /// a store or a load and a store into two or more instruction. If this is 344 /// possible, returns true as well as the new instructions by reference. 345 virtual bool unfoldMemoryOperand(MachineFunction &MF, MachineInstr *MI, 346 unsigned Reg, bool UnfoldLoad, bool UnfoldStore, 347 SmallVectorImpl<MachineInstr*> &NewMIs) const; 348 349 virtual bool unfoldMemoryOperand(SelectionDAG &DAG, SDNode *N, 350 SmallVectorImpl<SDNode*> &NewNodes) const; 351 352 /// getOpcodeAfterMemoryUnfold - Returns the opcode of the would be new 353 /// instruction after load / store are unfolded from an instruction of the 354 /// specified opcode. It returns zero if the specified unfolding is not 355 /// possible. 356 virtual unsigned getOpcodeAfterMemoryUnfold(unsigned Opc, 357 bool UnfoldLoad, bool UnfoldStore) const; 358 359 virtual bool BlockHasNoFallThrough(MachineBasicBlock &MBB) const; 360 virtual bool ReverseBranchCondition(std::vector<MachineOperand> &Cond) const; 361 362 const TargetRegisterClass *getPointerRegClass() const; 363 364 // getBaseOpcodeFor - This function returns the "base" X86 opcode for the 365 // specified machine instruction. 366 // 367 unsigned char getBaseOpcodeFor(const TargetInstrDesc *TID) const { 368 return TID->TSFlags >> X86II::OpcodeShift; 369 } 370 unsigned char getBaseOpcodeFor(unsigned Opcode) const { 371 return getBaseOpcodeFor(&get(Opcode)); 372 } 373 374private: 375 MachineInstr* foldMemoryOperand(MachineInstr* MI, 376 unsigned OpNum, 377 SmallVector<MachineOperand,4> &MOs) const; 378}; 379 380} // End llvm namespace 381 382#endif 383