IntrinsicLowering.cpp revision e4d87aa2de6e52952dca73716386db09aad5a8fd
1//===-- IntrinsicLowering.cpp - Intrinsic Lowering default implementation -===// 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 implements the IntrinsicLowering class. 11// 12//===----------------------------------------------------------------------===// 13 14#include "llvm/Constants.h" 15#include "llvm/DerivedTypes.h" 16#include "llvm/Module.h" 17#include "llvm/Instructions.h" 18#include "llvm/Type.h" 19#include "llvm/CodeGen/IntrinsicLowering.h" 20#include "llvm/Support/Streams.h" 21using namespace llvm; 22 23template <class ArgIt> 24static Function *EnsureFunctionExists(Module &M, const char *Name, 25 ArgIt ArgBegin, ArgIt ArgEnd, 26 const Type *RetTy) { 27 if (Function *F = M.getNamedFunction(Name)) return F; 28 // It doesn't already exist in the program, insert a new definition now. 29 std::vector<const Type *> ParamTys; 30 for (ArgIt I = ArgBegin; I != ArgEnd; ++I) 31 ParamTys.push_back(I->getType()); 32 return M.getOrInsertFunction(Name, FunctionType::get(RetTy, ParamTys, false)); 33} 34 35/// ReplaceCallWith - This function is used when we want to lower an intrinsic 36/// call to a call of an external function. This handles hard cases such as 37/// when there was already a prototype for the external function, and if that 38/// prototype doesn't match the arguments we expect to pass in. 39template <class ArgIt> 40static CallInst *ReplaceCallWith(const char *NewFn, CallInst *CI, 41 ArgIt ArgBegin, ArgIt ArgEnd, bool isSigned, 42 const Type *RetTy, Function *&FCache) { 43 if (!FCache) { 44 // If we haven't already looked up this function, check to see if the 45 // program already contains a function with this name. 46 Module *M = CI->getParent()->getParent()->getParent(); 47 FCache = M->getNamedFunction(NewFn); 48 if (!FCache) { 49 // It doesn't already exist in the program, insert a new definition now. 50 std::vector<const Type *> ParamTys; 51 for (ArgIt I = ArgBegin; I != ArgEnd; ++I) 52 ParamTys.push_back((*I)->getType()); 53 FCache = M->getOrInsertFunction(NewFn, 54 FunctionType::get(RetTy, ParamTys, false)); 55 } 56 } 57 58 const FunctionType *FT = FCache->getFunctionType(); 59 std::vector<Value*> Operands; 60 unsigned ArgNo = 0; 61 for (ArgIt I = ArgBegin; I != ArgEnd && ArgNo != FT->getNumParams(); 62 ++I, ++ArgNo) { 63 Value *Arg = *I; 64 if (Arg->getType() != FT->getParamType(ArgNo)) { 65 Instruction::CastOps opcode = CastInst::getCastOpcode(Arg, isSigned, 66 FT->getParamType(ArgNo), isSigned); 67 Arg = CastInst::create(opcode, Arg, FT->getParamType(ArgNo), 68 Arg->getName(), CI); 69 } 70 Operands.push_back(Arg); 71 } 72 // Pass nulls into any additional arguments... 73 for (; ArgNo != FT->getNumParams(); ++ArgNo) 74 Operands.push_back(Constant::getNullValue(FT->getParamType(ArgNo))); 75 76 std::string Name = CI->getName(); CI->setName(""); 77 if (FT->getReturnType() == Type::VoidTy) Name.clear(); 78 CallInst *NewCI = new CallInst(FCache, Operands, Name, CI); 79 if (!CI->use_empty()) { 80 Value *V = NewCI; 81 if (CI->getType() != NewCI->getType()) { 82 Instruction::CastOps opcode = CastInst::getCastOpcode(NewCI, isSigned, 83 CI->getType(), isSigned); 84 V = CastInst::create(opcode, NewCI, CI->getType(), Name, CI); 85 } 86 CI->replaceAllUsesWith(V); 87 } 88 return NewCI; 89} 90 91void IntrinsicLowering::AddPrototypes(Module &M) { 92 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) 93 if (I->isExternal() && !I->use_empty()) 94 switch (I->getIntrinsicID()) { 95 default: break; 96 case Intrinsic::setjmp: 97 EnsureFunctionExists(M, "setjmp", I->arg_begin(), I->arg_end(), 98 Type::IntTy); 99 break; 100 case Intrinsic::longjmp: 101 EnsureFunctionExists(M, "longjmp", I->arg_begin(), I->arg_end(), 102 Type::VoidTy); 103 break; 104 case Intrinsic::siglongjmp: 105 EnsureFunctionExists(M, "abort", I->arg_end(), I->arg_end(), 106 Type::VoidTy); 107 break; 108 case Intrinsic::memcpy_i32: 109 case Intrinsic::memcpy_i64: 110 EnsureFunctionExists(M, "memcpy", I->arg_begin(), --I->arg_end(), 111 I->arg_begin()->getType()); 112 break; 113 case Intrinsic::memmove_i32: 114 case Intrinsic::memmove_i64: 115 EnsureFunctionExists(M, "memmove", I->arg_begin(), --I->arg_end(), 116 I->arg_begin()->getType()); 117 break; 118 case Intrinsic::memset_i32: 119 case Intrinsic::memset_i64: 120 M.getOrInsertFunction("memset", PointerType::get(Type::SByteTy), 121 PointerType::get(Type::SByteTy), 122 Type::IntTy, (--(--I->arg_end()))->getType(), 123 (Type *)0); 124 break; 125 case Intrinsic::isunordered_f32: 126 case Intrinsic::isunordered_f64: 127 EnsureFunctionExists(M, "isunordered", I->arg_begin(), I->arg_end(), 128 Type::BoolTy); 129 break; 130 case Intrinsic::sqrt_f32: 131 case Intrinsic::sqrt_f64: 132 if(I->arg_begin()->getType() == Type::FloatTy) 133 EnsureFunctionExists(M, "sqrtf", I->arg_begin(), I->arg_end(), 134 Type::FloatTy); 135 else 136 EnsureFunctionExists(M, "sqrt", I->arg_begin(), I->arg_end(), 137 Type::DoubleTy); 138 break; 139 } 140} 141 142/// LowerBSWAP - Emit the code to lower bswap of V before the specified 143/// instruction IP. 144static Value *LowerBSWAP(Value *V, Instruction *IP) { 145 assert(V->getType()->isInteger() && "Can't bswap a non-integer type!"); 146 147 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 148 149 switch(BitSize) { 150 default: assert(0 && "Unhandled type size of value to byteswap!"); 151 case 16: { 152 Value *Tmp1 = new ShiftInst(Instruction::Shl, V, 153 ConstantInt::get(Type::UByteTy,8),"bswap.2",IP); 154 Value *Tmp2 = new ShiftInst(Instruction::LShr, V, 155 ConstantInt::get(Type::UByteTy,8),"bswap.1",IP); 156 V = BinaryOperator::createOr(Tmp1, Tmp2, "bswap.i16", IP); 157 break; 158 } 159 case 32: { 160 Value *Tmp4 = new ShiftInst(Instruction::Shl, V, 161 ConstantInt::get(Type::UByteTy,24),"bswap.4", IP); 162 Value *Tmp3 = new ShiftInst(Instruction::Shl, V, 163 ConstantInt::get(Type::UByteTy,8),"bswap.3",IP); 164 Value *Tmp2 = new ShiftInst(Instruction::LShr, V, 165 ConstantInt::get(Type::UByteTy,8),"bswap.2",IP); 166 Value *Tmp1 = new ShiftInst(Instruction::LShr, V, 167 ConstantInt::get(Type::UByteTy,24),"bswap.1", IP); 168 Tmp3 = BinaryOperator::createAnd(Tmp3, 169 ConstantInt::get(Type::UIntTy, 0xFF0000), 170 "bswap.and3", IP); 171 Tmp2 = BinaryOperator::createAnd(Tmp2, 172 ConstantInt::get(Type::UIntTy, 0xFF00), 173 "bswap.and2", IP); 174 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp3, "bswap.or1", IP); 175 Tmp2 = BinaryOperator::createOr(Tmp2, Tmp1, "bswap.or2", IP); 176 V = BinaryOperator::createOr(Tmp4, Tmp3, "bswap.i32", IP); 177 break; 178 } 179 case 64: { 180 Value *Tmp8 = new ShiftInst(Instruction::Shl, V, 181 ConstantInt::get(Type::UByteTy,56),"bswap.8", IP); 182 Value *Tmp7 = new ShiftInst(Instruction::Shl, V, 183 ConstantInt::get(Type::UByteTy,40),"bswap.7", IP); 184 Value *Tmp6 = new ShiftInst(Instruction::Shl, V, 185 ConstantInt::get(Type::UByteTy,24),"bswap.6", IP); 186 Value *Tmp5 = new ShiftInst(Instruction::Shl, V, 187 ConstantInt::get(Type::UByteTy,8),"bswap.5", IP); 188 Value* Tmp4 = new ShiftInst(Instruction::LShr, V, 189 ConstantInt::get(Type::UByteTy,8),"bswap.4", IP); 190 Value* Tmp3 = new ShiftInst(Instruction::LShr, V, 191 ConstantInt::get(Type::UByteTy,24),"bswap.3", IP); 192 Value* Tmp2 = new ShiftInst(Instruction::LShr, V, 193 ConstantInt::get(Type::UByteTy,40),"bswap.2", IP); 194 Value* Tmp1 = new ShiftInst(Instruction::LShr, V, 195 ConstantInt::get(Type::UByteTy,56),"bswap.1", IP); 196 Tmp7 = BinaryOperator::createAnd(Tmp7, 197 ConstantInt::get(Type::ULongTy, 198 0xFF000000000000ULL), 199 "bswap.and7", IP); 200 Tmp6 = BinaryOperator::createAnd(Tmp6, 201 ConstantInt::get(Type::ULongTy, 0xFF0000000000ULL), 202 "bswap.and6", IP); 203 Tmp5 = BinaryOperator::createAnd(Tmp5, 204 ConstantInt::get(Type::ULongTy, 0xFF00000000ULL), 205 "bswap.and5", IP); 206 Tmp4 = BinaryOperator::createAnd(Tmp4, 207 ConstantInt::get(Type::ULongTy, 0xFF000000ULL), 208 "bswap.and4", IP); 209 Tmp3 = BinaryOperator::createAnd(Tmp3, 210 ConstantInt::get(Type::ULongTy, 0xFF0000ULL), 211 "bswap.and3", IP); 212 Tmp2 = BinaryOperator::createAnd(Tmp2, 213 ConstantInt::get(Type::ULongTy, 0xFF00ULL), 214 "bswap.and2", IP); 215 Tmp8 = BinaryOperator::createOr(Tmp8, Tmp7, "bswap.or1", IP); 216 Tmp6 = BinaryOperator::createOr(Tmp6, Tmp5, "bswap.or2", IP); 217 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp3, "bswap.or3", IP); 218 Tmp2 = BinaryOperator::createOr(Tmp2, Tmp1, "bswap.or4", IP); 219 Tmp8 = BinaryOperator::createOr(Tmp8, Tmp6, "bswap.or5", IP); 220 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp2, "bswap.or6", IP); 221 V = BinaryOperator::createOr(Tmp8, Tmp4, "bswap.i64", IP); 222 break; 223 } 224 } 225 return V; 226} 227 228/// LowerCTPOP - Emit the code to lower ctpop of V before the specified 229/// instruction IP. 230static Value *LowerCTPOP(Value *V, Instruction *IP) { 231 assert(V->getType()->isInteger() && "Can't ctpop a non-integer type!"); 232 233 static const uint64_t MaskValues[6] = { 234 0x5555555555555555ULL, 0x3333333333333333ULL, 235 0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL, 236 0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL 237 }; 238 239 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 240 241 for (unsigned i = 1, ct = 0; i != BitSize; i <<= 1, ++ct) { 242 Value *MaskCst = ConstantInt::get(V->getType(), MaskValues[ct]); 243 Value *LHS = BinaryOperator::createAnd(V, MaskCst, "cppop.and1", IP); 244 Value *VShift = new ShiftInst(Instruction::LShr, V, 245 ConstantInt::get(Type::UByteTy, i), "ctpop.sh", IP); 246 Value *RHS = BinaryOperator::createAnd(VShift, MaskCst, "cppop.and2", IP); 247 V = BinaryOperator::createAdd(LHS, RHS, "ctpop.step", IP); 248 } 249 250 return V; 251} 252 253/// LowerCTLZ - Emit the code to lower ctlz of V before the specified 254/// instruction IP. 255static Value *LowerCTLZ(Value *V, Instruction *IP) { 256 257 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 258 for (unsigned i = 1; i != BitSize; i <<= 1) { 259 Value *ShVal = ConstantInt::get(Type::UByteTy, i); 260 ShVal = new ShiftInst(Instruction::LShr, V, ShVal, "ctlz.sh", IP); 261 V = BinaryOperator::createOr(V, ShVal, "ctlz.step", IP); 262 } 263 264 V = BinaryOperator::createNot(V, "", IP); 265 return LowerCTPOP(V, IP); 266} 267 268 269 270void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) { 271 Function *Callee = CI->getCalledFunction(); 272 assert(Callee && "Cannot lower an indirect call!"); 273 274 switch (Callee->getIntrinsicID()) { 275 case Intrinsic::not_intrinsic: 276 cerr << "Cannot lower a call to a non-intrinsic function '" 277 << Callee->getName() << "'!\n"; 278 abort(); 279 default: 280 cerr << "Error: Code generator does not support intrinsic function '" 281 << Callee->getName() << "'!\n"; 282 abort(); 283 284 // The setjmp/longjmp intrinsics should only exist in the code if it was 285 // never optimized (ie, right out of the CFE), or if it has been hacked on 286 // by the lowerinvoke pass. In both cases, the right thing to do is to 287 // convert the call to an explicit setjmp or longjmp call. 288 case Intrinsic::setjmp: { 289 static Function *SetjmpFCache = 0; 290 static const unsigned castOpcodes[] = { Instruction::BitCast }; 291 Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin()+1, CI->op_end(), 292 castOpcodes, Type::IntTy, SetjmpFCache); 293 if (CI->getType() != Type::VoidTy) 294 CI->replaceAllUsesWith(V); 295 break; 296 } 297 case Intrinsic::sigsetjmp: 298 if (CI->getType() != Type::VoidTy) 299 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 300 break; 301 302 case Intrinsic::longjmp: { 303 static Function *LongjmpFCache = 0; 304 static const unsigned castOpcodes[] = 305 { Instruction::BitCast, 0 }; 306 ReplaceCallWith("longjmp", CI, CI->op_begin()+1, CI->op_end(), 307 castOpcodes, Type::VoidTy, LongjmpFCache); 308 break; 309 } 310 311 case Intrinsic::siglongjmp: { 312 // Insert the call to abort 313 static Function *AbortFCache = 0; 314 static const unsigned castOpcodes[] = 315 { Instruction::BitCast, 0 }; 316 ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(), 317 castOpcodes, Type::VoidTy, AbortFCache); 318 break; 319 } 320 case Intrinsic::ctpop_i8: 321 case Intrinsic::ctpop_i16: 322 case Intrinsic::ctpop_i32: 323 case Intrinsic::ctpop_i64: 324 CI->replaceAllUsesWith(LowerCTPOP(CI->getOperand(1), CI)); 325 break; 326 327 case Intrinsic::bswap_i16: 328 case Intrinsic::bswap_i32: 329 case Intrinsic::bswap_i64: 330 CI->replaceAllUsesWith(LowerBSWAP(CI->getOperand(1), CI)); 331 break; 332 333 case Intrinsic::ctlz_i8: 334 case Intrinsic::ctlz_i16: 335 case Intrinsic::ctlz_i32: 336 case Intrinsic::ctlz_i64: 337 CI->replaceAllUsesWith(LowerCTLZ(CI->getOperand(1), CI)); 338 break; 339 340 case Intrinsic::cttz_i8: 341 case Intrinsic::cttz_i16: 342 case Intrinsic::cttz_i32: 343 case Intrinsic::cttz_i64: { 344 // cttz(x) -> ctpop(~X & (X-1)) 345 Value *Src = CI->getOperand(1); 346 Value *NotSrc = BinaryOperator::createNot(Src, Src->getName()+".not", CI); 347 Value *SrcM1 = ConstantInt::get(Src->getType(), 1); 348 SrcM1 = BinaryOperator::createSub(Src, SrcM1, "", CI); 349 Src = LowerCTPOP(BinaryOperator::createAnd(NotSrc, SrcM1, "", CI), CI); 350 CI->replaceAllUsesWith(Src); 351 break; 352 } 353 354 case Intrinsic::stacksave: 355 case Intrinsic::stackrestore: { 356 static bool Warned = false; 357 if (!Warned) 358 cerr << "WARNING: this target does not support the llvm.stack" 359 << (Callee->getIntrinsicID() == Intrinsic::stacksave ? 360 "save" : "restore") << " intrinsic.\n"; 361 Warned = true; 362 if (Callee->getIntrinsicID() == Intrinsic::stacksave) 363 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 364 break; 365 } 366 367 case Intrinsic::returnaddress: 368 case Intrinsic::frameaddress: 369 cerr << "WARNING: this target does not support the llvm." 370 << (Callee->getIntrinsicID() == Intrinsic::returnaddress ? 371 "return" : "frame") << "address intrinsic.\n"; 372 CI->replaceAllUsesWith(ConstantPointerNull::get( 373 cast<PointerType>(CI->getType()))); 374 break; 375 376 case Intrinsic::prefetch: 377 break; // Simply strip out prefetches on unsupported architectures 378 379 case Intrinsic::pcmarker: 380 break; // Simply strip out pcmarker on unsupported architectures 381 case Intrinsic::readcyclecounter: { 382 cerr << "WARNING: this target does not support the llvm.readcyclecoun" 383 << "ter intrinsic. It is being lowered to a constant 0\n"; 384 CI->replaceAllUsesWith(ConstantInt::get(Type::ULongTy, 0)); 385 break; 386 } 387 388 case Intrinsic::dbg_stoppoint: 389 case Intrinsic::dbg_region_start: 390 case Intrinsic::dbg_region_end: 391 case Intrinsic::dbg_func_start: 392 case Intrinsic::dbg_declare: 393 break; // Simply strip out debugging intrinsics 394 395 case Intrinsic::memcpy_i32: { 396 static Function *MemcpyFCache = 0; 397 ReplaceCallWith("memcpy", CI, CI->op_begin()+1, CI->op_end()-1, 398 false, (*(CI->op_begin()+1))->getType(), MemcpyFCache); 399 break; 400 } 401 case Intrinsic::memcpy_i64: { 402 static Function *MemcpyFCache = 0; 403 ReplaceCallWith("memcpy", CI, CI->op_begin()+1, CI->op_end()-1, 404 false, (*(CI->op_begin()+1))->getType(), MemcpyFCache); 405 break; 406 } 407 case Intrinsic::memmove_i32: { 408 static Function *MemmoveFCache = 0; 409 ReplaceCallWith("memmove", CI, CI->op_begin()+1, CI->op_end()-1, 410 false, (*(CI->op_begin()+1))->getType(), MemmoveFCache); 411 break; 412 } 413 case Intrinsic::memmove_i64: { 414 static Function *MemmoveFCache = 0; 415 ReplaceCallWith("memmove", CI, CI->op_begin()+1, CI->op_end()-1, 416 false, (*(CI->op_begin()+1))->getType(), MemmoveFCache); 417 break; 418 } 419 case Intrinsic::memset_i32: { 420 static Function *MemsetFCache = 0; 421 ReplaceCallWith("memset", CI, CI->op_begin()+1, CI->op_end()-1, 422 true, (*(CI->op_begin()+1))->getType(), MemsetFCache); 423 } 424 case Intrinsic::memset_i64: { 425 static Function *MemsetFCache = 0; 426 ReplaceCallWith("memset", CI, CI->op_begin()+1, CI->op_end()-1, 427 true, (*(CI->op_begin()+1))->getType(), MemsetFCache); 428 break; 429 } 430 case Intrinsic::isunordered_f32: 431 case Intrinsic::isunordered_f64: { 432 Value *L = CI->getOperand(1); 433 Value *R = CI->getOperand(2); 434 435 Value *LIsNan = new FCmpInst(FCmpInst::FCMP_ONE, L, L, "LIsNan", CI); 436 Value *RIsNan = new FCmpInst(FCmpInst::FCMP_ONE, R, R, "RIsNan", CI); 437 CI->replaceAllUsesWith( 438 BinaryOperator::create(Instruction::Or, LIsNan, RIsNan, 439 "isunordered", CI)); 440 break; 441 } 442 case Intrinsic::sqrt_f32: { 443 static Function *sqrtfFCache = 0; 444 ReplaceCallWith("sqrtf", CI, CI->op_begin()+1, CI->op_end(), 445 false, Type::FloatTy, sqrtfFCache); 446 break; 447 } 448 case Intrinsic::sqrt_f64: { 449 static Function *sqrtFCache = 0; 450 ReplaceCallWith("sqrt", CI, CI->op_begin()+1, CI->op_end(), 451 false, Type::DoubleTy, sqrtFCache); 452 break; 453 } 454 } 455 456 assert(CI->use_empty() && 457 "Lowering should have eliminated any uses of the intrinsic call!"); 458 CI->eraseFromParent(); 459} 460