IntrinsicLowering.cpp revision 0b118206bf3411722707f2e5cab8fd2eedcd50d6
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: 103 EnsureFunctionExists(M, "memcpy", I->arg_begin(), --I->arg_end(), 104 I->arg_begin()->getType()); 105 break; 106 case Intrinsic::memmove: 107 EnsureFunctionExists(M, "memmove", I->arg_begin(), --I->arg_end(), 108 I->arg_begin()->getType()); 109 break; 110 case Intrinsic::memset: 111 M.getOrInsertFunction("memset", PointerType::get(Type::SByteTy), 112 PointerType::get(Type::SByteTy), 113 Type::IntTy, (--(--I->arg_end()))->getType(), 114 (Type *)0); 115 break; 116 case Intrinsic::isunordered_f32: 117 case Intrinsic::isunordered_f64: 118 EnsureFunctionExists(M, "isunordered", I->arg_begin(), I->arg_end(), 119 Type::BoolTy); 120 break; 121 case Intrinsic::sqrt_f32: 122 case Intrinsic::sqrt_f64: 123 if(I->arg_begin()->getType() == Type::FloatTy) 124 EnsureFunctionExists(M, "sqrtf", I->arg_begin(), I->arg_end(), 125 Type::FloatTy); 126 else 127 EnsureFunctionExists(M, "sqrt", I->arg_begin(), I->arg_end(), 128 Type::DoubleTy); 129 break; 130 } 131} 132 133/// LowerBSWAP - Emit the code to lower bswap of V before the specified 134/// instruction IP. 135static Value *LowerBSWAP(Value *V, Instruction *IP) { 136 assert(V->getType()->isInteger() && "Can't bswap a non-integer type!"); 137 138 const Type *DestTy = V->getType(); 139 140 // Force to unsigned so that the shift rights are logical. 141 if (DestTy->isSigned()) 142 V = new CastInst(V, DestTy->getUnsignedVersion(), V->getName(), IP); 143 144 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 145 146 switch(BitSize) { 147 default: assert(0 && "Unhandled type size of value to byteswap!"); 148 case 16: { 149 Value *Tmp1 = new ShiftInst(Instruction::Shl, V, 150 ConstantInt::get(Type::UByteTy,8),"bswap.2",IP); 151 Value *Tmp2 = new ShiftInst(Instruction::Shr, V, 152 ConstantInt::get(Type::UByteTy,8),"bswap.1",IP); 153 V = BinaryOperator::createOr(Tmp1, Tmp2, "bswap.i16", IP); 154 break; 155 } 156 case 32: { 157 Value *Tmp4 = new ShiftInst(Instruction::Shl, V, 158 ConstantInt::get(Type::UByteTy,24),"bswap.4", IP); 159 Value *Tmp3 = new ShiftInst(Instruction::Shl, V, 160 ConstantInt::get(Type::UByteTy,8),"bswap.3",IP); 161 Value *Tmp2 = new ShiftInst(Instruction::Shr, V, 162 ConstantInt::get(Type::UByteTy,8),"bswap.2",IP); 163 Value *Tmp1 = new ShiftInst(Instruction::Shr, V, 164 ConstantInt::get(Type::UByteTy,24),"bswap.1", IP); 165 Tmp3 = BinaryOperator::createAnd(Tmp3, 166 ConstantUInt::get(Type::UIntTy, 0xFF0000), 167 "bswap.and3", IP); 168 Tmp2 = BinaryOperator::createAnd(Tmp2, 169 ConstantUInt::get(Type::UIntTy, 0xFF00), 170 "bswap.and2", IP); 171 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp3, "bswap.or1", IP); 172 Tmp2 = BinaryOperator::createOr(Tmp2, Tmp1, "bswap.or2", IP); 173 V = BinaryOperator::createOr(Tmp4, Tmp3, "bswap.i32", IP); 174 break; 175 } 176 case 64: { 177 Value *Tmp8 = new ShiftInst(Instruction::Shl, V, 178 ConstantInt::get(Type::UByteTy,56),"bswap.8", IP); 179 Value *Tmp7 = new ShiftInst(Instruction::Shl, V, 180 ConstantInt::get(Type::UByteTy,40),"bswap.7", IP); 181 Value *Tmp6 = new ShiftInst(Instruction::Shl, V, 182 ConstantInt::get(Type::UByteTy,24),"bswap.6", IP); 183 Value *Tmp5 = new ShiftInst(Instruction::Shl, V, 184 ConstantInt::get(Type::UByteTy,8),"bswap.5",IP); 185 Value *Tmp4 = new ShiftInst(Instruction::Shr, V, 186 ConstantInt::get(Type::UByteTy,8),"bswap.4",IP); 187 Value *Tmp3 = new ShiftInst(Instruction::Shr, V, 188 ConstantInt::get(Type::UByteTy,24),"bswap.3", IP); 189 Value *Tmp2 = new ShiftInst(Instruction::Shr, V, 190 ConstantInt::get(Type::UByteTy,40),"bswap.2", IP); 191 Value *Tmp1 = new ShiftInst(Instruction::Shr, V, 192 ConstantInt::get(Type::UByteTy,56),"bswap.1", IP); 193 Tmp7 = BinaryOperator::createAnd(Tmp7, 194 ConstantUInt::get(Type::ULongTy, 0xFF000000000000ULL), 195 "bswap.and7", IP); 196 Tmp6 = BinaryOperator::createAnd(Tmp6, 197 ConstantUInt::get(Type::ULongTy, 0xFF0000000000ULL), 198 "bswap.and6", IP); 199 Tmp5 = BinaryOperator::createAnd(Tmp5, 200 ConstantUInt::get(Type::ULongTy, 0xFF00000000ULL), 201 "bswap.and5", IP); 202 Tmp4 = BinaryOperator::createAnd(Tmp4, 203 ConstantUInt::get(Type::ULongTy, 0xFF000000ULL), 204 "bswap.and4", IP); 205 Tmp3 = BinaryOperator::createAnd(Tmp3, 206 ConstantUInt::get(Type::ULongTy, 0xFF0000ULL), 207 "bswap.and3", IP); 208 Tmp2 = BinaryOperator::createAnd(Tmp2, 209 ConstantUInt::get(Type::ULongTy, 0xFF00ULL), 210 "bswap.and2", IP); 211 Tmp8 = BinaryOperator::createOr(Tmp8, Tmp7, "bswap.or1", IP); 212 Tmp6 = BinaryOperator::createOr(Tmp6, Tmp5, "bswap.or2", IP); 213 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp3, "bswap.or3", IP); 214 Tmp2 = BinaryOperator::createOr(Tmp2, Tmp1, "bswap.or4", IP); 215 Tmp8 = BinaryOperator::createOr(Tmp8, Tmp6, "bswap.or5", IP); 216 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp2, "bswap.or6", IP); 217 V = BinaryOperator::createOr(Tmp8, Tmp4, "bswap.i64", IP); 218 break; 219 } 220 } 221 222 if (V->getType() != DestTy) 223 V = new CastInst(V, DestTy, V->getName(), IP); 224 return V; 225} 226 227/// LowerCTPOP - Emit the code to lower ctpop of V before the specified 228/// instruction IP. 229static Value *LowerCTPOP(Value *V, Instruction *IP) { 230 assert(V->getType()->isInteger() && "Can't ctpop a non-integer type!"); 231 232 static const uint64_t MaskValues[6] = { 233 0x5555555555555555ULL, 0x3333333333333333ULL, 234 0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL, 235 0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL 236 }; 237 238 const Type *DestTy = V->getType(); 239 240 // Force to unsigned so that the shift rights are logical. 241 if (DestTy->isSigned()) 242 V = new CastInst(V, DestTy->getUnsignedVersion(), V->getName(), IP); 243 244 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 245 for (unsigned i = 1, ct = 0; i != BitSize; i <<= 1, ++ct) { 246 Value *MaskCst = 247 ConstantExpr::getCast(ConstantUInt::get(Type::ULongTy, 248 MaskValues[ct]), V->getType()); 249 Value *LHS = BinaryOperator::createAnd(V, MaskCst, "cppop.and1", IP); 250 Value *VShift = new ShiftInst(Instruction::Shr, V, 251 ConstantInt::get(Type::UByteTy, i), "ctpop.sh", IP); 252 Value *RHS = BinaryOperator::createAnd(VShift, MaskCst, "cppop.and2", IP); 253 V = BinaryOperator::createAdd(LHS, RHS, "ctpop.step", IP); 254 } 255 256 if (V->getType() != DestTy) 257 V = new CastInst(V, DestTy, V->getName(), IP); 258 return V; 259} 260 261/// LowerCTLZ - Emit the code to lower ctlz of V before the specified 262/// instruction IP. 263static Value *LowerCTLZ(Value *V, Instruction *IP) { 264 const Type *DestTy = V->getType(); 265 266 // Force to unsigned so that the shift rights are logical. 267 if (DestTy->isSigned()) 268 V = new CastInst(V, DestTy->getUnsignedVersion(), V->getName(), IP); 269 270 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 271 for (unsigned i = 1; i != BitSize; i <<= 1) { 272 Value *ShVal = ConstantInt::get(Type::UByteTy, i); 273 ShVal = new ShiftInst(Instruction::Shr, V, ShVal, "ctlz.sh", IP); 274 V = BinaryOperator::createOr(V, ShVal, "ctlz.step", IP); 275 } 276 277 if (V->getType() != DestTy) 278 V = new CastInst(V, DestTy, V->getName(), IP); 279 280 V = BinaryOperator::createNot(V, "", IP); 281 return LowerCTPOP(V, IP); 282} 283 284 285 286void DefaultIntrinsicLowering::LowerIntrinsicCall(CallInst *CI) { 287 Function *Callee = CI->getCalledFunction(); 288 assert(Callee && "Cannot lower an indirect call!"); 289 290 switch (Callee->getIntrinsicID()) { 291 case Intrinsic::not_intrinsic: 292 std::cerr << "Cannot lower a call to a non-intrinsic function '" 293 << Callee->getName() << "'!\n"; 294 abort(); 295 default: 296 std::cerr << "Error: Code generator does not support intrinsic function '" 297 << Callee->getName() << "'!\n"; 298 abort(); 299 300 // The setjmp/longjmp intrinsics should only exist in the code if it was 301 // never optimized (ie, right out of the CFE), or if it has been hacked on 302 // by the lowerinvoke pass. In both cases, the right thing to do is to 303 // convert the call to an explicit setjmp or longjmp call. 304 case Intrinsic::setjmp: { 305 static Function *SetjmpFCache = 0; 306 Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin()+1, CI->op_end(), 307 Type::IntTy, SetjmpFCache); 308 if (CI->getType() != Type::VoidTy) 309 CI->replaceAllUsesWith(V); 310 break; 311 } 312 case Intrinsic::sigsetjmp: 313 if (CI->getType() != Type::VoidTy) 314 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 315 break; 316 317 case Intrinsic::longjmp: { 318 static Function *LongjmpFCache = 0; 319 ReplaceCallWith("longjmp", CI, CI->op_begin()+1, CI->op_end(), 320 Type::VoidTy, LongjmpFCache); 321 break; 322 } 323 324 case Intrinsic::siglongjmp: { 325 // Insert the call to abort 326 static Function *AbortFCache = 0; 327 ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(), Type::VoidTy, 328 AbortFCache); 329 break; 330 } 331 case Intrinsic::ctpop_i8: 332 case Intrinsic::ctpop_i16: 333 case Intrinsic::ctpop_i32: 334 case Intrinsic::ctpop_i64: 335 CI->replaceAllUsesWith(LowerCTPOP(CI->getOperand(1), CI)); 336 break; 337 338 case Intrinsic::bswap_i16: 339 case Intrinsic::bswap_i32: 340 case Intrinsic::bswap_i64: 341 CI->replaceAllUsesWith(LowerBSWAP(CI->getOperand(1), CI)); 342 break; 343 344 case Intrinsic::ctlz_i8: 345 case Intrinsic::ctlz_i16: 346 case Intrinsic::ctlz_i32: 347 case Intrinsic::ctlz_i64: 348 CI->replaceAllUsesWith(LowerCTLZ(CI->getOperand(1), CI)); 349 break; 350 351 case Intrinsic::cttz_i8: 352 case Intrinsic::cttz_i16: 353 case Intrinsic::cttz_i32: 354 case Intrinsic::cttz_i64: { 355 // cttz(x) -> ctpop(~X & (X-1)) 356 Value *Src = CI->getOperand(1); 357 Value *NotSrc = BinaryOperator::createNot(Src, Src->getName()+".not", CI); 358 Value *SrcM1 = ConstantInt::get(Src->getType(), 1); 359 SrcM1 = BinaryOperator::createSub(Src, SrcM1, "", CI); 360 Src = LowerCTPOP(BinaryOperator::createAnd(NotSrc, SrcM1, "", CI), CI); 361 CI->replaceAllUsesWith(Src); 362 break; 363 } 364 365 case Intrinsic::stacksave: 366 case Intrinsic::stackrestore: { 367 static bool Warned = false; 368 if (!Warned) 369 std::cerr << "WARNING: this target does not support the llvm.stack" 370 << (Callee->getIntrinsicID() == Intrinsic::stacksave ? 371 "save" : "restore") << " intrinsic.\n"; 372 Warned = true; 373 if (Callee->getIntrinsicID() == Intrinsic::stacksave) 374 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 375 break; 376 } 377 378 case Intrinsic::returnaddress: 379 case Intrinsic::frameaddress: 380 std::cerr << "WARNING: this target does not support the llvm." 381 << (Callee->getIntrinsicID() == Intrinsic::returnaddress ? 382 "return" : "frame") << "address intrinsic.\n"; 383 CI->replaceAllUsesWith(ConstantPointerNull::get( 384 cast<PointerType>(CI->getType()))); 385 break; 386 387 case Intrinsic::prefetch: 388 break; // Simply strip out prefetches on unsupported architectures 389 390 case Intrinsic::pcmarker: 391 break; // Simply strip out pcmarker on unsupported architectures 392 case Intrinsic::readcyclecounter: { 393 std::cerr << "WARNING: this target does not support the llvm.readcyclecoun" 394 << "ter intrinsic. It is being lowered to a constant 0\n"; 395 CI->replaceAllUsesWith(ConstantUInt::get(Type::ULongTy, 0)); 396 break; 397 } 398 399 case Intrinsic::dbg_stoppoint: 400 case Intrinsic::dbg_region_start: 401 case Intrinsic::dbg_region_end: 402 case Intrinsic::dbg_declare: 403 case Intrinsic::dbg_func_start: 404 if (CI->getType() != Type::VoidTy) 405 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 406 break; // Simply strip out debugging intrinsics 407 408 case Intrinsic::memcpy: { 409 // The memcpy intrinsic take an extra alignment argument that the memcpy 410 // libc function does not. 411 static Function *MemcpyFCache = 0; 412 ReplaceCallWith("memcpy", CI, CI->op_begin()+1, CI->op_end()-1, 413 (*(CI->op_begin()+1))->getType(), MemcpyFCache); 414 break; 415 } 416 case Intrinsic::memmove: { 417 // The memmove intrinsic take an extra alignment argument that the memmove 418 // libc function does not. 419 static Function *MemmoveFCache = 0; 420 ReplaceCallWith("memmove", CI, CI->op_begin()+1, CI->op_end()-1, 421 (*(CI->op_begin()+1))->getType(), MemmoveFCache); 422 break; 423 } 424 case Intrinsic::memset: { 425 // The memset intrinsic take an extra alignment argument that the memset 426 // libc function does not. 427 static Function *MemsetFCache = 0; 428 ReplaceCallWith("memset", CI, CI->op_begin()+1, CI->op_end()-1, 429 (*(CI->op_begin()+1))->getType(), MemsetFCache); 430 break; 431 } 432 case Intrinsic::isunordered_f32: 433 case Intrinsic::isunordered_f64: { 434 Value *L = CI->getOperand(1); 435 Value *R = CI->getOperand(2); 436 437 Value *LIsNan = new SetCondInst(Instruction::SetNE, L, L, "LIsNan", CI); 438 Value *RIsNan = new SetCondInst(Instruction::SetNE, R, R, "RIsNan", CI); 439 CI->replaceAllUsesWith( 440 BinaryOperator::create(Instruction::Or, LIsNan, RIsNan, 441 "isunordered", CI)); 442 break; 443 } 444 case Intrinsic::sqrt_f32: 445 case Intrinsic::sqrt_f64: { 446 static Function *sqrtFCache = 0; 447 static Function *sqrtfFCache = 0; 448 if(CI->getType() == Type::FloatTy) 449 ReplaceCallWith("sqrtf", CI, CI->op_begin()+1, CI->op_end(), 450 Type::FloatTy, sqrtfFCache); 451 else 452 ReplaceCallWith("sqrt", CI, CI->op_begin()+1, CI->op_end(), 453 Type::DoubleTy, sqrtFCache); 454 break; 455 } 456 } 457 458 assert(CI->use_empty() && 459 "Lowering should have eliminated any uses of the intrinsic call!"); 460 CI->eraseFromParent(); 461} 462