IntrinsicLowering.cpp revision b83eb6447ba155342598f0fabe1f08f5baa9164a
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 default intrinsic lowering implementation. 11// 12//===----------------------------------------------------------------------===// 13 14#include "llvm/CodeGen/IntrinsicLowering.h" 15#include "llvm/Constants.h" 16#include "llvm/DerivedTypes.h" 17#include "llvm/Module.h" 18#include "llvm/Instructions.h" 19#include "llvm/Type.h" 20#include <iostream> 21 22using namespace llvm; 23 24template <class ArgIt> 25static Function *EnsureFunctionExists(Module &M, const char *Name, 26 ArgIt ArgBegin, ArgIt ArgEnd, 27 const Type *RetTy) { 28 if (Function *F = M.getNamedFunction(Name)) return F; 29 // It doesn't already exist in the program, insert a new definition now. 30 std::vector<const Type *> ParamTys; 31 for (ArgIt I = ArgBegin; I != ArgEnd; ++I) 32 ParamTys.push_back(I->getType()); 33 return M.getOrInsertFunction(Name, FunctionType::get(RetTy, ParamTys, false)); 34} 35 36/// ReplaceCallWith - This function is used when we want to lower an intrinsic 37/// call to a call of an external function. This handles hard cases such as 38/// when there was already a prototype for the external function, and if that 39/// prototype doesn't match the arguments we expect to pass in. 40template <class ArgIt> 41static CallInst *ReplaceCallWith(const char *NewFn, CallInst *CI, 42 ArgIt ArgBegin, ArgIt ArgEnd, 43 const Type *RetTy, Function *&FCache) { 44 if (!FCache) { 45 // If we haven't already looked up this function, check to see if the 46 // program already contains a function with this name. 47 Module *M = CI->getParent()->getParent()->getParent(); 48 FCache = M->getNamedFunction(NewFn); 49 if (!FCache) { 50 // It doesn't already exist in the program, insert a new definition now. 51 std::vector<const Type *> ParamTys; 52 for (ArgIt I = ArgBegin; I != ArgEnd; ++I) 53 ParamTys.push_back((*I)->getType()); 54 FCache = M->getOrInsertFunction(NewFn, 55 FunctionType::get(RetTy, ParamTys, false)); 56 } 57 } 58 59 const FunctionType *FT = FCache->getFunctionType(); 60 std::vector<Value*> Operands; 61 unsigned ArgNo = 0; 62 for (ArgIt I = ArgBegin; I != ArgEnd && ArgNo != FT->getNumParams(); 63 ++I, ++ArgNo) { 64 Value *Arg = *I; 65 if (Arg->getType() != FT->getParamType(ArgNo)) 66 Arg = new CastInst(Arg, FT->getParamType(ArgNo), Arg->getName(), CI); 67 Operands.push_back(Arg); 68 } 69 // Pass nulls into any additional arguments... 70 for (; ArgNo != FT->getNumParams(); ++ArgNo) 71 Operands.push_back(Constant::getNullValue(FT->getParamType(ArgNo))); 72 73 std::string Name = CI->getName(); CI->setName(""); 74 if (FT->getReturnType() == Type::VoidTy) Name.clear(); 75 CallInst *NewCI = new CallInst(FCache, Operands, Name, CI); 76 if (!CI->use_empty()) { 77 Value *V = NewCI; 78 if (CI->getType() != NewCI->getType()) 79 V = new CastInst(NewCI, CI->getType(), Name, CI); 80 CI->replaceAllUsesWith(V); 81 } 82 return NewCI; 83} 84 85void DefaultIntrinsicLowering::AddPrototypes(Module &M) { 86 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) 87 if (I->isExternal() && !I->use_empty()) 88 switch (I->getIntrinsicID()) { 89 default: break; 90 case Intrinsic::setjmp: 91 EnsureFunctionExists(M, "setjmp", I->arg_begin(), I->arg_end(), 92 Type::IntTy); 93 break; 94 case Intrinsic::longjmp: 95 EnsureFunctionExists(M, "longjmp", I->arg_begin(), I->arg_end(), 96 Type::VoidTy); 97 break; 98 case Intrinsic::siglongjmp: 99 EnsureFunctionExists(M, "abort", I->arg_end(), I->arg_end(), 100 Type::VoidTy); 101 break; 102 case Intrinsic::memcpy_i32: 103 case Intrinsic::memcpy_i64: 104 EnsureFunctionExists(M, "memcpy", I->arg_begin(), --I->arg_end(), 105 I->arg_begin()->getType()); 106 break; 107 case Intrinsic::memmove_i32: 108 case Intrinsic::memmove_i64: 109 EnsureFunctionExists(M, "memmove", I->arg_begin(), --I->arg_end(), 110 I->arg_begin()->getType()); 111 break; 112 case Intrinsic::memset_i32: 113 case Intrinsic::memset_i64: 114 M.getOrInsertFunction("memset", PointerType::get(Type::SByteTy), 115 PointerType::get(Type::SByteTy), 116 Type::IntTy, (--(--I->arg_end()))->getType(), 117 (Type *)0); 118 break; 119 case Intrinsic::isunordered_f32: 120 case Intrinsic::isunordered_f64: 121 EnsureFunctionExists(M, "isunordered", I->arg_begin(), I->arg_end(), 122 Type::BoolTy); 123 break; 124 case Intrinsic::sqrt_f32: 125 case Intrinsic::sqrt_f64: 126 if(I->arg_begin()->getType() == Type::FloatTy) 127 EnsureFunctionExists(M, "sqrtf", I->arg_begin(), I->arg_end(), 128 Type::FloatTy); 129 else 130 EnsureFunctionExists(M, "sqrt", I->arg_begin(), I->arg_end(), 131 Type::DoubleTy); 132 break; 133 } 134} 135 136/// LowerBSWAP - Emit the code to lower bswap of V before the specified 137/// instruction IP. 138static Value *LowerBSWAP(Value *V, Instruction *IP) { 139 assert(V->getType()->isInteger() && "Can't bswap a non-integer type!"); 140 141 const Type *DestTy = V->getType(); 142 143 // Force to unsigned so that the shift rights are logical. 144 if (DestTy->isSigned()) 145 V = new CastInst(V, DestTy->getUnsignedVersion(), V->getName(), IP); 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::Shr, 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::Shr, V, 165 ConstantInt::get(Type::UByteTy,8),"bswap.2",IP); 166 Value *Tmp1 = new ShiftInst(Instruction::Shr, 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::Shr, V, 189 ConstantInt::get(Type::UByteTy,8),"bswap.4",IP); 190 Value *Tmp3 = new ShiftInst(Instruction::Shr, V, 191 ConstantInt::get(Type::UByteTy,24),"bswap.3", IP); 192 Value *Tmp2 = new ShiftInst(Instruction::Shr, V, 193 ConstantInt::get(Type::UByteTy,40),"bswap.2", IP); 194 Value *Tmp1 = new ShiftInst(Instruction::Shr, 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 } 225 226 if (V->getType() != DestTy) 227 V = new CastInst(V, DestTy, V->getName(), IP); 228 return V; 229} 230 231/// LowerCTPOP - Emit the code to lower ctpop of V before the specified 232/// instruction IP. 233static Value *LowerCTPOP(Value *V, Instruction *IP) { 234 assert(V->getType()->isInteger() && "Can't ctpop a non-integer type!"); 235 236 static const uint64_t MaskValues[6] = { 237 0x5555555555555555ULL, 0x3333333333333333ULL, 238 0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL, 239 0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL 240 }; 241 242 const Type *DestTy = V->getType(); 243 244 // Force to unsigned so that the shift rights are logical. 245 if (DestTy->isSigned()) 246 V = new CastInst(V, DestTy->getUnsignedVersion(), V->getName(), IP); 247 248 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 249 for (unsigned i = 1, ct = 0; i != BitSize; i <<= 1, ++ct) { 250 Value *MaskCst = 251 ConstantExpr::getCast(ConstantInt::get(Type::ULongTy, MaskValues[ct]), 252 V->getType()); 253 Value *LHS = BinaryOperator::createAnd(V, MaskCst, "cppop.and1", IP); 254 Value *VShift = new ShiftInst(Instruction::Shr, V, 255 ConstantInt::get(Type::UByteTy, i), "ctpop.sh", IP); 256 Value *RHS = BinaryOperator::createAnd(VShift, MaskCst, "cppop.and2", IP); 257 V = BinaryOperator::createAdd(LHS, RHS, "ctpop.step", IP); 258 } 259 260 if (V->getType() != DestTy) 261 V = new CastInst(V, DestTy, V->getName(), IP); 262 return V; 263} 264 265/// LowerCTLZ - Emit the code to lower ctlz of V before the specified 266/// instruction IP. 267static Value *LowerCTLZ(Value *V, Instruction *IP) { 268 const Type *DestTy = V->getType(); 269 270 // Force to unsigned so that the shift rights are logical. 271 if (DestTy->isSigned()) 272 V = new CastInst(V, DestTy->getUnsignedVersion(), V->getName(), IP); 273 274 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 275 for (unsigned i = 1; i != BitSize; i <<= 1) { 276 Value *ShVal = ConstantInt::get(Type::UByteTy, i); 277 ShVal = new ShiftInst(Instruction::Shr, V, ShVal, "ctlz.sh", IP); 278 V = BinaryOperator::createOr(V, ShVal, "ctlz.step", IP); 279 } 280 281 if (V->getType() != DestTy) 282 V = new CastInst(V, DestTy, V->getName(), IP); 283 284 V = BinaryOperator::createNot(V, "", IP); 285 return LowerCTPOP(V, IP); 286} 287 288 289 290void DefaultIntrinsicLowering::LowerIntrinsicCall(CallInst *CI) { 291 Function *Callee = CI->getCalledFunction(); 292 assert(Callee && "Cannot lower an indirect call!"); 293 294 switch (Callee->getIntrinsicID()) { 295 case Intrinsic::not_intrinsic: 296 std::cerr << "Cannot lower a call to a non-intrinsic function '" 297 << Callee->getName() << "'!\n"; 298 abort(); 299 default: 300 std::cerr << "Error: Code generator does not support intrinsic function '" 301 << Callee->getName() << "'!\n"; 302 abort(); 303 304 // The setjmp/longjmp intrinsics should only exist in the code if it was 305 // never optimized (ie, right out of the CFE), or if it has been hacked on 306 // by the lowerinvoke pass. In both cases, the right thing to do is to 307 // convert the call to an explicit setjmp or longjmp call. 308 case Intrinsic::setjmp: { 309 static Function *SetjmpFCache = 0; 310 Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin()+1, CI->op_end(), 311 Type::IntTy, SetjmpFCache); 312 if (CI->getType() != Type::VoidTy) 313 CI->replaceAllUsesWith(V); 314 break; 315 } 316 case Intrinsic::sigsetjmp: 317 if (CI->getType() != Type::VoidTy) 318 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 319 break; 320 321 case Intrinsic::longjmp: { 322 static Function *LongjmpFCache = 0; 323 ReplaceCallWith("longjmp", CI, CI->op_begin()+1, CI->op_end(), 324 Type::VoidTy, LongjmpFCache); 325 break; 326 } 327 328 case Intrinsic::siglongjmp: { 329 // Insert the call to abort 330 static Function *AbortFCache = 0; 331 ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(), Type::VoidTy, 332 AbortFCache); 333 break; 334 } 335 case Intrinsic::ctpop_i8: 336 case Intrinsic::ctpop_i16: 337 case Intrinsic::ctpop_i32: 338 case Intrinsic::ctpop_i64: 339 CI->replaceAllUsesWith(LowerCTPOP(CI->getOperand(1), CI)); 340 break; 341 342 case Intrinsic::bswap_i16: 343 case Intrinsic::bswap_i32: 344 case Intrinsic::bswap_i64: 345 CI->replaceAllUsesWith(LowerBSWAP(CI->getOperand(1), CI)); 346 break; 347 348 case Intrinsic::ctlz_i8: 349 case Intrinsic::ctlz_i16: 350 case Intrinsic::ctlz_i32: 351 case Intrinsic::ctlz_i64: 352 CI->replaceAllUsesWith(LowerCTLZ(CI->getOperand(1), CI)); 353 break; 354 355 case Intrinsic::cttz_i8: 356 case Intrinsic::cttz_i16: 357 case Intrinsic::cttz_i32: 358 case Intrinsic::cttz_i64: { 359 // cttz(x) -> ctpop(~X & (X-1)) 360 Value *Src = CI->getOperand(1); 361 Value *NotSrc = BinaryOperator::createNot(Src, Src->getName()+".not", CI); 362 Value *SrcM1 = ConstantInt::get(Src->getType(), 1); 363 SrcM1 = BinaryOperator::createSub(Src, SrcM1, "", CI); 364 Src = LowerCTPOP(BinaryOperator::createAnd(NotSrc, SrcM1, "", CI), CI); 365 CI->replaceAllUsesWith(Src); 366 break; 367 } 368 369 case Intrinsic::stacksave: 370 case Intrinsic::stackrestore: { 371 static bool Warned = false; 372 if (!Warned) 373 std::cerr << "WARNING: this target does not support the llvm.stack" 374 << (Callee->getIntrinsicID() == Intrinsic::stacksave ? 375 "save" : "restore") << " intrinsic.\n"; 376 Warned = true; 377 if (Callee->getIntrinsicID() == Intrinsic::stacksave) 378 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 379 break; 380 } 381 382 case Intrinsic::returnaddress: 383 case Intrinsic::frameaddress: 384 std::cerr << "WARNING: this target does not support the llvm." 385 << (Callee->getIntrinsicID() == Intrinsic::returnaddress ? 386 "return" : "frame") << "address intrinsic.\n"; 387 CI->replaceAllUsesWith(ConstantPointerNull::get( 388 cast<PointerType>(CI->getType()))); 389 break; 390 391 case Intrinsic::prefetch: 392 break; // Simply strip out prefetches on unsupported architectures 393 394 case Intrinsic::pcmarker: 395 break; // Simply strip out pcmarker on unsupported architectures 396 case Intrinsic::readcyclecounter: { 397 std::cerr << "WARNING: this target does not support the llvm.readcyclecoun" 398 << "ter intrinsic. It is being lowered to a constant 0\n"; 399 CI->replaceAllUsesWith(ConstantInt::get(Type::ULongTy, 0)); 400 break; 401 } 402 403 case Intrinsic::dbg_stoppoint: 404 case Intrinsic::dbg_region_start: 405 case Intrinsic::dbg_region_end: 406 case Intrinsic::dbg_func_start: 407 case Intrinsic::dbg_declare: 408 break; // Simply strip out debugging intrinsics 409 410 case Intrinsic::memcpy_i32: 411 case Intrinsic::memcpy_i64: { 412 // The memcpy intrinsic take an extra alignment argument that the memcpy 413 // libc function does not. 414 static Function *MemcpyFCache = 0; 415 ReplaceCallWith("memcpy", CI, CI->op_begin()+1, CI->op_end()-1, 416 (*(CI->op_begin()+1))->getType(), MemcpyFCache); 417 break; 418 } 419 case Intrinsic::memmove_i32: 420 case Intrinsic::memmove_i64: { 421 // The memmove intrinsic take an extra alignment argument that the memmove 422 // libc function does not. 423 static Function *MemmoveFCache = 0; 424 ReplaceCallWith("memmove", CI, CI->op_begin()+1, CI->op_end()-1, 425 (*(CI->op_begin()+1))->getType(), MemmoveFCache); 426 break; 427 } 428 case Intrinsic::memset_i32: 429 case Intrinsic::memset_i64: { 430 // The memset intrinsic take an extra alignment argument that the memset 431 // libc function does not. 432 static Function *MemsetFCache = 0; 433 ReplaceCallWith("memset", CI, CI->op_begin()+1, CI->op_end()-1, 434 (*(CI->op_begin()+1))->getType(), MemsetFCache); 435 break; 436 } 437 case Intrinsic::isunordered_f32: 438 case Intrinsic::isunordered_f64: { 439 Value *L = CI->getOperand(1); 440 Value *R = CI->getOperand(2); 441 442 Value *LIsNan = new SetCondInst(Instruction::SetNE, L, L, "LIsNan", CI); 443 Value *RIsNan = new SetCondInst(Instruction::SetNE, R, R, "RIsNan", CI); 444 CI->replaceAllUsesWith( 445 BinaryOperator::create(Instruction::Or, LIsNan, RIsNan, 446 "isunordered", CI)); 447 break; 448 } 449 case Intrinsic::sqrt_f32: 450 case Intrinsic::sqrt_f64: { 451 static Function *sqrtFCache = 0; 452 static Function *sqrtfFCache = 0; 453 if(CI->getType() == Type::FloatTy) 454 ReplaceCallWith("sqrtf", CI, CI->op_begin()+1, CI->op_end(), 455 Type::FloatTy, sqrtfFCache); 456 else 457 ReplaceCallWith("sqrt", CI, CI->op_begin()+1, CI->op_end(), 458 Type::DoubleTy, sqrtFCache); 459 break; 460 } 461 } 462 463 assert(CI->use_empty() && 464 "Lowering should have eliminated any uses of the intrinsic call!"); 465 CI->eraseFromParent(); 466} 467