TargetInstrInfo.h revision 6fbcc26f1460eaee4e0eb8b426fc1ff0c7af11be
1//===-- llvm/Target/TargetInstrInfo.h - Instruction Info --------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file was developed by the LLVM research group and is distributed under 6// the University of Illinois Open Source License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file describes the target machine instructions to the code generator. 11// 12//===----------------------------------------------------------------------===// 13 14#ifndef LLVM_TARGET_TARGETINSTRINFO_H 15#define LLVM_TARGET_TARGETINSTRINFO_H 16 17#include "Support/DataTypes.h" 18#include <vector> 19#include <cassert> 20 21class MachineInstr; 22class TargetMachine; 23class Value; 24class Type; 25class Instruction; 26class Constant; 27class Function; 28class MachineCodeForInstruction; 29 30//--------------------------------------------------------------------------- 31// Data types used to define information about a single machine instruction 32//--------------------------------------------------------------------------- 33 34typedef int MachineOpCode; 35typedef unsigned InstrSchedClass; 36 37const MachineOpCode INVALID_MACHINE_OPCODE = -1; 38 39 40//--------------------------------------------------------------------------- 41// struct TargetInstrDescriptor: 42// Predefined information about each machine instruction. 43// Designed to initialized statically. 44// 45 46const unsigned M_NOP_FLAG = 1 << 0; 47const unsigned M_BRANCH_FLAG = 1 << 1; 48const unsigned M_CALL_FLAG = 1 << 2; 49const unsigned M_RET_FLAG = 1 << 3; 50const unsigned M_ARITH_FLAG = 1 << 4; 51const unsigned M_CC_FLAG = 1 << 6; 52const unsigned M_LOGICAL_FLAG = 1 << 6; 53const unsigned M_INT_FLAG = 1 << 7; 54const unsigned M_FLOAT_FLAG = 1 << 8; 55const unsigned M_CONDL_FLAG = 1 << 9; 56const unsigned M_LOAD_FLAG = 1 << 10; 57const unsigned M_PREFETCH_FLAG = 1 << 11; 58const unsigned M_STORE_FLAG = 1 << 12; 59const unsigned M_DUMMY_PHI_FLAG = 1 << 13; 60const unsigned M_PSEUDO_FLAG = 1 << 14; // Pseudo instruction 61// 3-addr instructions which really work like 2-addr ones, eg. X86 add/sub 62const unsigned M_2_ADDR_FLAG = 1 << 15; 63 64// M_TERMINATOR_FLAG - Is this instruction part of the terminator for a basic 65// block? Typically this is things like return and branch instructions. 66// Various passes use this to insert code into the bottom of a basic block, but 67// before control flow occurs. 68const unsigned M_TERMINATOR_FLAG = 1 << 16; 69 70struct TargetInstrDescriptor { 71 const char * Name; // Assembly language mnemonic for the opcode. 72 int numOperands; // Number of args; -1 if variable #args 73 int resultPos; // Position of the result; -1 if no result 74 unsigned maxImmedConst; // Largest +ve constant in IMMMED field or 0. 75 bool immedIsSignExtended; // Is IMMED field sign-extended? If so, 76 // smallest -ve value is -(maxImmedConst+1). 77 unsigned numDelaySlots; // Number of delay slots after instruction 78 unsigned latency; // Latency in machine cycles 79 InstrSchedClass schedClass; // enum identifying instr sched class 80 unsigned Flags; // flags identifying machine instr class 81 unsigned TSFlags; // Target Specific Flag values 82 const unsigned *ImplicitUses; // Registers implicitly read by this instr 83 const unsigned *ImplicitDefs; // Registers implicitly defined by this instr 84}; 85 86 87//--------------------------------------------------------------------------- 88/// 89/// TargetInstrInfo - Interface to description of machine instructions 90/// 91class TargetInstrInfo { 92 const TargetInstrDescriptor* desc; // raw array to allow static init'n 93 unsigned descSize; // number of entries in the desc array 94 unsigned numRealOpCodes; // number of non-dummy op codes 95 96 TargetInstrInfo(const TargetInstrInfo &); // DO NOT IMPLEMENT 97 void operator=(const TargetInstrInfo &); // DO NOT IMPLEMENT 98public: 99 TargetInstrInfo(const TargetInstrDescriptor *desc, unsigned descSize, 100 unsigned numRealOpCodes); 101 virtual ~TargetInstrInfo(); 102 103 // Invariant: All instruction sets use opcode #0 as the PHI instruction 104 enum { PHI = 0 }; 105 106 unsigned getNumRealOpCodes() const { return numRealOpCodes; } 107 unsigned getNumTotalOpCodes() const { return descSize; } 108 109 /// get - Return the machine instruction descriptor that corresponds to the 110 /// specified instruction opcode. 111 /// 112 const TargetInstrDescriptor& get(MachineOpCode opCode) const { 113 assert(opCode >= 0 && opCode < (int)descSize); 114 return desc[opCode]; 115 } 116 117 const char *getName(MachineOpCode opCode) const { 118 return get(opCode).Name; 119 } 120 121 int getNumOperands(MachineOpCode opCode) const { 122 return get(opCode).numOperands; 123 } 124 125 int getResultPos(MachineOpCode opCode) const { 126 return get(opCode).resultPos; 127 } 128 129 unsigned getNumDelaySlots(MachineOpCode opCode) const { 130 return get(opCode).numDelaySlots; 131 } 132 133 InstrSchedClass getSchedClass(MachineOpCode opCode) const { 134 return get(opCode).schedClass; 135 } 136 137 const unsigned *getImplicitUses(MachineOpCode opCode) const { 138 return get(opCode).ImplicitUses; 139 } 140 141 const unsigned *getImplicitDefs(MachineOpCode opCode) const { 142 return get(opCode).ImplicitDefs; 143 } 144 145 // 146 // Query instruction class flags according to the machine-independent 147 // flags listed above. 148 // 149 bool isNop(MachineOpCode opCode) const { 150 return get(opCode).Flags & M_NOP_FLAG; 151 } 152 bool isBranch(MachineOpCode opCode) const { 153 return get(opCode).Flags & M_BRANCH_FLAG; 154 } 155 bool isCall(MachineOpCode opCode) const { 156 return get(opCode).Flags & M_CALL_FLAG; 157 } 158 bool isReturn(MachineOpCode opCode) const { 159 return get(opCode).Flags & M_RET_FLAG; 160 } 161 bool isControlFlow(MachineOpCode opCode) const { 162 return get(opCode).Flags & M_BRANCH_FLAG 163 || get(opCode).Flags & M_CALL_FLAG 164 || get(opCode).Flags & M_RET_FLAG; 165 } 166 bool isArith(MachineOpCode opCode) const { 167 return get(opCode).Flags & M_ARITH_FLAG; 168 } 169 bool isCCInstr(MachineOpCode opCode) const { 170 return get(opCode).Flags & M_CC_FLAG; 171 } 172 bool isLogical(MachineOpCode opCode) const { 173 return get(opCode).Flags & M_LOGICAL_FLAG; 174 } 175 bool isIntInstr(MachineOpCode opCode) const { 176 return get(opCode).Flags & M_INT_FLAG; 177 } 178 bool isFloatInstr(MachineOpCode opCode) const { 179 return get(opCode).Flags & M_FLOAT_FLAG; 180 } 181 bool isConditional(MachineOpCode opCode) const { 182 return get(opCode).Flags & M_CONDL_FLAG; 183 } 184 bool isLoad(MachineOpCode opCode) const { 185 return get(opCode).Flags & M_LOAD_FLAG; 186 } 187 bool isPrefetch(MachineOpCode opCode) const { 188 return get(opCode).Flags & M_PREFETCH_FLAG; 189 } 190 bool isLoadOrPrefetch(MachineOpCode opCode) const { 191 return get(opCode).Flags & M_LOAD_FLAG 192 || get(opCode).Flags & M_PREFETCH_FLAG; 193 } 194 bool isStore(MachineOpCode opCode) const { 195 return get(opCode).Flags & M_STORE_FLAG; 196 } 197 bool isMemoryAccess(MachineOpCode opCode) const { 198 return get(opCode).Flags & M_LOAD_FLAG 199 || get(opCode).Flags & M_PREFETCH_FLAG 200 || get(opCode).Flags & M_STORE_FLAG; 201 } 202 bool isDummyPhiInstr(MachineOpCode opCode) const { 203 return get(opCode).Flags & M_DUMMY_PHI_FLAG; 204 } 205 bool isPseudoInstr(MachineOpCode opCode) const { 206 return get(opCode).Flags & M_PSEUDO_FLAG; 207 } 208 bool isTwoAddrInstr(MachineOpCode opCode) const { 209 return get(opCode).Flags & M_2_ADDR_FLAG; 210 } 211 bool isTerminatorInstr(unsigned Opcode) const { 212 return get(Opcode).Flags & M_TERMINATOR_FLAG; 213 } 214 215 // Check if an instruction can be issued before its operands are ready, 216 // or if a subsequent instruction that uses its result can be issued 217 // before the results are ready. 218 // Default to true since most instructions on many architectures allow this. 219 // 220 virtual bool hasOperandInterlock(MachineOpCode opCode) const { 221 return true; 222 } 223 224 virtual bool hasResultInterlock(MachineOpCode opCode) const { 225 return true; 226 } 227 228 // 229 // Latencies for individual instructions and instruction pairs 230 // 231 virtual int minLatency(MachineOpCode opCode) const { 232 return get(opCode).latency; 233 } 234 235 virtual int maxLatency(MachineOpCode opCode) const { 236 return get(opCode).latency; 237 } 238 239 // 240 // Which operand holds an immediate constant? Returns -1 if none 241 // 242 virtual int getImmedConstantPos(MachineOpCode opCode) const { 243 return -1; // immediate position is machine specific, so say -1 == "none" 244 } 245 246 // Check if the specified constant fits in the immediate field 247 // of this machine instruction 248 // 249 virtual bool constantFitsInImmedField(MachineOpCode opCode, 250 int64_t intValue) const; 251 252 // Return the largest +ve constant that can be held in the IMMMED field 253 // of this machine instruction. 254 // isSignExtended is set to true if the value is sign-extended before use 255 // (this is true for all immediate fields in SPARC instructions). 256 // Return 0 if the instruction has no IMMED field. 257 // 258 virtual uint64_t maxImmedConstant(MachineOpCode opCode, 259 bool &isSignExtended) const { 260 isSignExtended = get(opCode).immedIsSignExtended; 261 return get(opCode).maxImmedConst; 262 } 263 264 //------------------------------------------------------------------------- 265 // Queries about representation of LLVM quantities (e.g., constants) 266 //------------------------------------------------------------------------- 267 268 /// ConstantTypeMustBeLoaded - Test if this type of constant must be loaded 269 /// from memory into a register, i.e., cannot be set bitwise in register and 270 /// cannot use immediate fields of instructions. Note that this only makes 271 /// sense for primitive types. 272 /// 273 virtual bool ConstantTypeMustBeLoaded(const Constant* CV) const; 274 275 // Test if this constant may not fit in the immediate field of the 276 // machine instructions (probably) generated for this instruction. 277 // 278 virtual bool ConstantMayNotFitInImmedField(const Constant* CV, 279 const Instruction* I) const { 280 return true; // safe but very conservative 281 } 282 283 284 /// createNOPinstr - returns the target's implementation of NOP, which is 285 /// usually a pseudo-instruction, implemented by a degenerate version of 286 /// another instruction, e.g. X86: xchg ax, ax; SparcV9: sethi g0, 0 287 /// 288 virtual MachineInstr* createNOPinstr() const = 0; 289 290 /// isNOPinstr - not having a special NOP opcode, we need to know if a given 291 /// instruction is interpreted as an `official' NOP instr, i.e., there may be 292 /// more than one way to `do nothing' but only one canonical way to slack off. 293 /// 294 virtual bool isNOPinstr(const MachineInstr &MI) const = 0; 295 296 //------------------------------------------------------------------------- 297 // Code generation support for creating individual machine instructions 298 // 299 // WARNING: These methods are Sparc specific 300 // 301 //------------------------------------------------------------------------- 302 303 // Get certain common op codes for the current target. this and all the 304 // Create* methods below should be moved to a machine code generation class 305 // 306 virtual MachineOpCode getNOPOpCode() const { abort(); } 307 308 // Get the value of an integral constant in the form that must 309 // be put into the machine register. The specified constant is interpreted 310 // as (i.e., converted if necessary to) the specified destination type. The 311 // result is always returned as an uint64_t, since the representation of 312 // int64_t and uint64_t are identical. The argument can be any known const. 313 // 314 // isValidConstant is set to true if a valid constant was found. 315 // 316 virtual uint64_t ConvertConstantToIntType(const TargetMachine &target, 317 const Value *V, 318 const Type *destType, 319 bool &isValidConstant) const { 320 abort(); 321 } 322 323 // Create an instruction sequence to put the constant `val' into 324 // the virtual register `dest'. `val' may be a Constant or a 325 // GlobalValue, viz., the constant address of a global variable or function. 326 // The generated instructions are returned in `mvec'. 327 // Any temp. registers (TmpInstruction) created are recorded in mcfi. 328 // Symbolic constants or constants that must be accessed from memory 329 // are added to the constant pool via MachineFunction::get(F). 330 // 331 virtual void CreateCodeToLoadConst(const TargetMachine& target, 332 Function* F, 333 Value* val, 334 Instruction* dest, 335 std::vector<MachineInstr*>& mvec, 336 MachineCodeForInstruction& mcfi) const { 337 abort(); 338 } 339 340 // Create an instruction sequence to copy an integer value `val' 341 // to a floating point value `dest' by copying to memory and back. 342 // val must be an integral type. dest must be a Float or Double. 343 // The generated instructions are returned in `mvec'. 344 // Any temp. registers (TmpInstruction) created are recorded in mcfi. 345 // Any stack space required is allocated via mcff. 346 // 347 virtual void CreateCodeToCopyIntToFloat(const TargetMachine& target, 348 Function* F, 349 Value* val, 350 Instruction* dest, 351 std::vector<MachineInstr*>& mvec, 352 MachineCodeForInstruction& MI) const { 353 abort(); 354 } 355 356 // Similarly, create an instruction sequence to copy an FP value 357 // `val' to an integer value `dest' by copying to memory and back. 358 // The generated instructions are returned in `mvec'. 359 // Any temp. registers (TmpInstruction) created are recorded in mcfi. 360 // Any stack space required is allocated via mcff. 361 // 362 virtual void CreateCodeToCopyFloatToInt(const TargetMachine& target, 363 Function* F, 364 Value* val, 365 Instruction* dest, 366 std::vector<MachineInstr*>& mvec, 367 MachineCodeForInstruction& MI) const { 368 abort(); 369 } 370 371 // Create instruction(s) to copy src to dest, for arbitrary types 372 // The generated instructions are returned in `mvec'. 373 // Any temp. registers (TmpInstruction) created are recorded in mcfi. 374 // Any stack space required is allocated via mcff. 375 // 376 virtual void CreateCopyInstructionsByType(const TargetMachine& target, 377 Function* F, 378 Value* src, 379 Instruction* dest, 380 std::vector<MachineInstr*>& mvec, 381 MachineCodeForInstruction& MI) const { 382 abort(); 383 } 384 385 // Create instruction sequence to produce a sign-extended register value 386 // from an arbitrary sized value (sized in bits, not bytes). 387 // The generated instructions are appended to `mvec'. 388 // Any temp. registers (TmpInstruction) created are recorded in mcfi. 389 // Any stack space required is allocated via mcff. 390 // 391 virtual void CreateSignExtensionInstructions(const TargetMachine& target, 392 Function* F, 393 Value* srcVal, 394 Value* destVal, 395 unsigned numLowBits, 396 std::vector<MachineInstr*>& mvec, 397 MachineCodeForInstruction& MI) const { 398 abort(); 399 } 400 401 // Create instruction sequence to produce a zero-extended register value 402 // from an arbitrary sized value (sized in bits, not bytes). 403 // The generated instructions are appended to `mvec'. 404 // Any temp. registers (TmpInstruction) created are recorded in mcfi. 405 // Any stack space required is allocated via mcff. 406 // 407 virtual void CreateZeroExtensionInstructions(const TargetMachine& target, 408 Function* F, 409 Value* srcVal, 410 Value* destVal, 411 unsigned srcSizeInBits, 412 std::vector<MachineInstr*>& mvec, 413 MachineCodeForInstruction& mcfi) const { 414 abort(); 415 } 416}; 417 418#endif 419