TargetInstrInfo.h revision 502374a58fcd1c28065170a8c4a210be002ff190
1//===-- llvm/Target/InstrInfo.h - Target Instruction Information --*-C++-*-==// 2// 3// This file describes the target machine instructions to the code generator. 4// 5//===---------------------------------------------------------------------===// 6 7#ifndef LLVM_TARGET_MACHINEINSTRINFO_H 8#define LLVM_TARGET_MACHINEINSTRINFO_H 9 10#include "Support/NonCopyable.h" 11#include "Support/DataTypes.h" 12#include "llvm/Constant.h" 13#include "llvm/DerivedTypes.h" 14 15class MachineInstrDescriptor; 16class TmpInstruction; 17class MachineInstr; 18class TargetMachine; 19class Value; 20class Instruction; 21class Function; 22class MachineCodeForInstruction; 23 24//--------------------------------------------------------------------------- 25// Data types used to define information about a single machine instruction 26//--------------------------------------------------------------------------- 27 28typedef int MachineOpCode; 29typedef int OpCodeMask; 30typedef int InstrSchedClass; 31 32const MachineOpCode INVALID_MACHINE_OPCODE = -1; 33 34 35// Global variable holding an array of descriptors for machine instructions. 36// The actual object needs to be created separately for each target machine. 37// This variable is initialized and reset by class MachineInstrInfo. 38// 39// FIXME: This should be a property of the target so that more than one target 40// at a time can be active... 41// 42extern const MachineInstrDescriptor *TargetInstrDescriptors; 43 44 45//--------------------------------------------------------------------------- 46// struct MachineInstrDescriptor: 47// Predefined information about each machine instruction. 48// Designed to initialized statically. 49// 50// class MachineInstructionInfo 51// Interface to description of machine instructions 52// 53//--------------------------------------------------------------------------- 54 55 56const unsigned int M_NOP_FLAG = 1 << 0; 57const unsigned int M_BRANCH_FLAG = 1 << 1; 58const unsigned int M_CALL_FLAG = 1 << 2; 59const unsigned int M_RET_FLAG = 1 << 3; 60const unsigned int M_ARITH_FLAG = 1 << 4; 61const unsigned int M_CC_FLAG = 1 << 6; 62const unsigned int M_LOGICAL_FLAG = 1 << 6; 63const unsigned int M_INT_FLAG = 1 << 7; 64const unsigned int M_FLOAT_FLAG = 1 << 8; 65const unsigned int M_CONDL_FLAG = 1 << 9; 66const unsigned int M_LOAD_FLAG = 1 << 10; 67const unsigned int M_PREFETCH_FLAG = 1 << 11; 68const unsigned int M_STORE_FLAG = 1 << 12; 69const unsigned int M_DUMMY_PHI_FLAG = 1 << 13; 70const unsigned int M_PSEUDO_FLAG = 1 << 14; 71 72 73struct MachineInstrDescriptor { 74 std::string opCodeString; // Assembly language mnemonic for the opcode. 75 int numOperands; // Number of args; -1 if variable #args 76 int resultPos; // Position of the result; -1 if no result 77 unsigned int maxImmedConst; // Largest +ve constant in IMMMED field or 0. 78 bool immedIsSignExtended; // Is IMMED field sign-extended? If so, 79 // smallest -ve value is -(maxImmedConst+1). 80 unsigned int numDelaySlots; // Number of delay slots after instruction 81 unsigned int latency; // Latency in machine cycles 82 InstrSchedClass schedClass; // enum identifying instr sched class 83 unsigned int iclass; // flags identifying machine instr class 84}; 85 86 87class MachineInstrInfo : public NonCopyableV { 88public: 89 const TargetMachine& target; 90 91protected: 92 const MachineInstrDescriptor* desc; // raw array to allow static init'n 93 unsigned int descSize; // number of entries in the desc array 94 unsigned int numRealOpCodes; // number of non-dummy op codes 95 96public: 97 MachineInstrInfo(const TargetMachine& tgt, 98 const MachineInstrDescriptor *desc, unsigned descSize, 99 unsigned numRealOpCodes); 100 virtual ~MachineInstrInfo(); 101 102 unsigned getNumRealOpCodes() const { return numRealOpCodes; } 103 unsigned getNumTotalOpCodes() const { return descSize; } 104 105 const MachineInstrDescriptor& getDescriptor(MachineOpCode opCode) const { 106 assert(opCode >= 0 && opCode < (int)descSize); 107 return desc[opCode]; 108 } 109 110 int getNumOperands(MachineOpCode opCode) const { 111 return getDescriptor(opCode).numOperands; 112 } 113 114 int getResultPos(MachineOpCode opCode) const { 115 return getDescriptor(opCode).resultPos; 116 } 117 118 unsigned getNumDelaySlots(MachineOpCode opCode) const { 119 return getDescriptor(opCode).numDelaySlots; 120 } 121 122 InstrSchedClass getSchedClass(MachineOpCode opCode) const { 123 return getDescriptor(opCode).schedClass; 124 } 125 126 // 127 // Query instruction class flags according to the machine-independent 128 // flags listed above. 129 // 130 unsigned int getIClass(MachineOpCode opCode) const { 131 return getDescriptor(opCode).iclass; 132 } 133 bool isNop(MachineOpCode opCode) const { 134 return getDescriptor(opCode).iclass & M_NOP_FLAG; 135 } 136 bool isBranch(MachineOpCode opCode) const { 137 return getDescriptor(opCode).iclass & M_BRANCH_FLAG; 138 } 139 bool isCall(MachineOpCode opCode) const { 140 return getDescriptor(opCode).iclass & M_CALL_FLAG; 141 } 142 bool isReturn(MachineOpCode opCode) const { 143 return getDescriptor(opCode).iclass & M_RET_FLAG; 144 } 145 bool isControlFlow(MachineOpCode opCode) const { 146 return getDescriptor(opCode).iclass & M_BRANCH_FLAG 147 || getDescriptor(opCode).iclass & M_CALL_FLAG 148 || getDescriptor(opCode).iclass & M_RET_FLAG; 149 } 150 bool isArith(MachineOpCode opCode) const { 151 return getDescriptor(opCode).iclass & M_ARITH_FLAG; 152 } 153 bool isCCInstr(MachineOpCode opCode) const { 154 return getDescriptor(opCode).iclass & M_CC_FLAG; 155 } 156 bool isLogical(MachineOpCode opCode) const { 157 return getDescriptor(opCode).iclass & M_LOGICAL_FLAG; 158 } 159 bool isIntInstr(MachineOpCode opCode) const { 160 return getDescriptor(opCode).iclass & M_INT_FLAG; 161 } 162 bool isFloatInstr(MachineOpCode opCode) const { 163 return getDescriptor(opCode).iclass & M_FLOAT_FLAG; 164 } 165 bool isConditional(MachineOpCode opCode) const { 166 return getDescriptor(opCode).iclass & M_CONDL_FLAG; 167 } 168 bool isLoad(MachineOpCode opCode) const { 169 return getDescriptor(opCode).iclass & M_LOAD_FLAG; 170 } 171 bool isPrefetch(MachineOpCode opCode) const { 172 return getDescriptor(opCode).iclass & M_PREFETCH_FLAG; 173 } 174 bool isLoadOrPrefetch(MachineOpCode opCode) const { 175 return getDescriptor(opCode).iclass & M_LOAD_FLAG 176 || getDescriptor(opCode).iclass & M_PREFETCH_FLAG; 177 } 178 bool isStore(MachineOpCode opCode) const { 179 return getDescriptor(opCode).iclass & M_STORE_FLAG; 180 } 181 bool isMemoryAccess(MachineOpCode opCode) const { 182 return getDescriptor(opCode).iclass & M_LOAD_FLAG 183 || getDescriptor(opCode).iclass & M_PREFETCH_FLAG 184 || getDescriptor(opCode).iclass & M_STORE_FLAG; 185 } 186 bool isDummyPhiInstr(const MachineOpCode opCode) const { 187 return getDescriptor(opCode).iclass & M_DUMMY_PHI_FLAG; 188 } 189 bool isPseudoInstr(const MachineOpCode opCode) const { 190 return getDescriptor(opCode).iclass & M_PSEUDO_FLAG; 191 } 192 193 // Check if an instruction can be issued before its operands are ready, 194 // or if a subsequent instruction that uses its result can be issued 195 // before the results are ready. 196 // Default to true since most instructions on many architectures allow this. 197 // 198 virtual bool hasOperandInterlock(MachineOpCode opCode) const { 199 return true; 200 } 201 202 virtual bool hasResultInterlock(MachineOpCode opCode) const { 203 return true; 204 } 205 206 // 207 // Latencies for individual instructions and instruction pairs 208 // 209 virtual int minLatency(MachineOpCode opCode) const { 210 return getDescriptor(opCode).latency; 211 } 212 213 virtual int maxLatency(MachineOpCode opCode) const { 214 return getDescriptor(opCode).latency; 215 } 216 217 // 218 // Which operand holds an immediate constant? Returns -1 if none 219 // 220 virtual int getImmedConstantPos(MachineOpCode opCode) const { 221 return -1; // immediate position is machine specific, so say -1 == "none" 222 } 223 224 // Check if the specified constant fits in the immediate field 225 // of this machine instruction 226 // 227 virtual bool constantFitsInImmedField(MachineOpCode opCode, 228 int64_t intValue) const; 229 230 // Return the largest +ve constant that can be held in the IMMMED field 231 // of this machine instruction. 232 // isSignExtended is set to true if the value is sign-extended before use 233 // (this is true for all immediate fields in SPARC instructions). 234 // Return 0 if the instruction has no IMMED field. 235 // 236 virtual uint64_t maxImmedConstant(MachineOpCode opCode, 237 bool &isSignExtended) const { 238 isSignExtended = getDescriptor(opCode).immedIsSignExtended; 239 return getDescriptor(opCode).maxImmedConst; 240 } 241 242 //------------------------------------------------------------------------- 243 // Queries about representation of LLVM quantities (e.g., constants) 244 //------------------------------------------------------------------------- 245 246 // Test if this type of constant must be loaded from memory into 247 // a register, i.e., cannot be set bitwise in register and cannot 248 // use immediate fields of instructions. Note that this only makes 249 // sense for primitive types. 250 virtual bool ConstantTypeMustBeLoaded(const Constant* CV) const { 251 assert(CV->getType()->isPrimitiveType() || isa<PointerType>(CV->getType())); 252 return !(CV->getType()->isIntegral() || isa<PointerType>(CV->getType())); 253 } 254 255 // Test if this constant may not fit in the immediate field of the 256 // machine instructions (probably) generated for this instruction. 257 // 258 virtual bool ConstantMayNotFitInImmedField(const Constant* CV, 259 const Instruction* I) const { 260 return true; // safe but very conservative 261 } 262 263 //------------------------------------------------------------------------- 264 // Code generation support for creating individual machine instructions 265 //------------------------------------------------------------------------- 266 267 // Get certain common op codes for the current target. this and all the 268 // Create* methods below should be moved to a machine code generation class 269 // 270 virtual MachineOpCode getNOPOpCode() const = 0; 271 272 // Create an instruction sequence to put the constant `val' into 273 // the virtual register `dest'. `val' may be a Constant or a 274 // GlobalValue, viz., the constant address of a global variable or function. 275 // The generated instructions are returned in `mvec'. 276 // Any temp. registers (TmpInstruction) created are recorded in mcfi. 277 // Symbolic constants or constants that must be accessed from memory 278 // are added to the constant pool via MachineCodeForMethod::get(F). 279 // 280 virtual void CreateCodeToLoadConst(const TargetMachine& target, 281 Function* F, 282 Value* val, 283 Instruction* dest, 284 std::vector<MachineInstr*>& mvec, 285 MachineCodeForInstruction& mcfi) const=0; 286 287 // Create an instruction sequence to copy an integer value `val' 288 // to a floating point value `dest' by copying to memory and back. 289 // val must be an integral type. dest must be a Float or Double. 290 // The generated instructions are returned in `mvec'. 291 // Any temp. registers (TmpInstruction) created are recorded in mcfi. 292 // Any stack space required is allocated via mcff. 293 // 294 virtual void CreateCodeToCopyIntToFloat(const TargetMachine& target, 295 Function* F, 296 Value* val, 297 Instruction* dest, 298 std::vector<MachineInstr*>& mvec, 299 MachineCodeForInstruction& mcfi)const=0; 300 301 // Similarly, create an instruction sequence to copy an FP value 302 // `val' to an integer value `dest' by copying to memory and back. 303 // The generated instructions are returned in `mvec'. 304 // Any temp. registers (TmpInstruction) created are recorded in mcfi. 305 // Any stack space required is allocated via mcff. 306 // 307 virtual void CreateCodeToCopyFloatToInt(const TargetMachine& target, 308 Function* F, 309 Value* val, 310 Instruction* dest, 311 std::vector<MachineInstr*>& mvec, 312 MachineCodeForInstruction& mcfi)const=0; 313 314 // Create instruction(s) to copy src to dest, for arbitrary types 315 // The generated instructions are returned in `mvec'. 316 // Any temp. registers (TmpInstruction) created are recorded in mcfi. 317 // Any stack space required is allocated via mcff. 318 // 319 virtual void CreateCopyInstructionsByType(const TargetMachine& target, 320 Function* F, 321 Value* src, 322 Instruction* dest, 323 std::vector<MachineInstr*>& mvec, 324 MachineCodeForInstruction& mcfi)const=0; 325 326 // Create instruction sequence to produce a sign-extended register value 327 // from an arbitrary sized value (sized in bits, not bytes). 328 // The generated instructions are appended to `mvec'. 329 // Any temp. registers (TmpInstruction) created are recorded in mcfi. 330 // Any stack space required is allocated via mcff. 331 // 332 virtual void CreateSignExtensionInstructions(const TargetMachine& target, 333 Function* F, 334 Value* srcVal, 335 Value* destVal, 336 unsigned int numLowBits, 337 std::vector<MachineInstr*>& mvec, 338 MachineCodeForInstruction& mcfi) const=0; 339 340 // Create instruction sequence to produce a zero-extended register value 341 // from an arbitrary sized value (sized in bits, not bytes). 342 // The generated instructions are appended to `mvec'. 343 // Any temp. registers (TmpInstruction) created are recorded in mcfi. 344 // Any stack space required is allocated via mcff. 345 // 346 virtual void CreateZeroExtensionInstructions(const TargetMachine& target, 347 Function* F, 348 Value* srcVal, 349 Value* destVal, 350 unsigned int srcSizeInBits, 351 std::vector<MachineInstr*>& mvec, 352 MachineCodeForInstruction& mcfi) const=0; 353}; 354 355#endif 356