IntrinsicLowering.cpp revision b41b5e0b2d865f9dcb8cc868b28929daf3a11207
1//===-- IntrinsicLowering.cpp - Intrinsic Lowering default implementation -===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// 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/Type.h" 18#include "llvm/CodeGen/IntrinsicLowering.h" 19#include "llvm/Support/IRBuilder.h" 20#include "llvm/Target/TargetData.h" 21#include "llvm/ADT/SmallVector.h" 22using namespace llvm; 23 24template <class ArgIt> 25static void EnsureFunctionExists(Module &M, const char *Name, 26 ArgIt ArgBegin, ArgIt ArgEnd, 27 const Type *RetTy) { 28 // Insert a correctly-typed definition now. 29 std::vector<const Type *> ParamTys; 30 for (ArgIt I = ArgBegin; I != ArgEnd; ++I) 31 ParamTys.push_back(I->getType()); 32 M.getOrInsertFunction(Name, FunctionType::get(RetTy, ParamTys, false)); 33} 34 35static void EnsureFPIntrinsicsExist(Module &M, Function *Fn, 36 const char *FName, 37 const char *DName, const char *LDName) { 38 // Insert definitions for all the floating point types. 39 switch((int)Fn->arg_begin()->getType()->getTypeID()) { 40 case Type::FloatTyID: 41 EnsureFunctionExists(M, FName, Fn->arg_begin(), Fn->arg_end(), 42 Type::FloatTy); 43 break; 44 case Type::DoubleTyID: 45 EnsureFunctionExists(M, DName, Fn->arg_begin(), Fn->arg_end(), 46 Type::DoubleTy); 47 break; 48 case Type::X86_FP80TyID: 49 case Type::FP128TyID: 50 case Type::PPC_FP128TyID: 51 EnsureFunctionExists(M, LDName, Fn->arg_begin(), Fn->arg_end(), 52 Fn->arg_begin()->getType()); 53 break; 54 } 55} 56 57/// ReplaceCallWith - This function is used when we want to lower an intrinsic 58/// call to a call of an external function. This handles hard cases such as 59/// when there was already a prototype for the external function, and if that 60/// prototype doesn't match the arguments we expect to pass in. 61template <class ArgIt> 62static CallInst *ReplaceCallWith(const char *NewFn, CallInst *CI, 63 ArgIt ArgBegin, ArgIt ArgEnd, 64 const Type *RetTy) { 65 // If we haven't already looked up this function, check to see if the 66 // program already contains a function with this name. 67 Module *M = CI->getParent()->getParent()->getParent(); 68 // Get or insert the definition now. 69 std::vector<const Type *> ParamTys; 70 for (ArgIt I = ArgBegin; I != ArgEnd; ++I) 71 ParamTys.push_back((*I)->getType()); 72 Constant* FCache = M->getOrInsertFunction(NewFn, 73 FunctionType::get(RetTy, ParamTys, false)); 74 75 IRBuilder<> Builder(CI->getParent(), CI); 76 SmallVector<Value *, 8> Args(ArgBegin, ArgEnd); 77 CallInst *NewCI = Builder.CreateCall(FCache, Args.begin(), Args.end()); 78 NewCI->setName(CI->getName()); 79 if (!CI->use_empty()) 80 CI->replaceAllUsesWith(NewCI); 81 return NewCI; 82} 83 84void IntrinsicLowering::AddPrototypes(Module &M) { 85 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) 86 if (I->isDeclaration() && !I->use_empty()) 87 switch (I->getIntrinsicID()) { 88 default: break; 89 case Intrinsic::setjmp: 90 EnsureFunctionExists(M, "setjmp", I->arg_begin(), I->arg_end(), 91 Type::Int32Ty); 92 break; 93 case Intrinsic::longjmp: 94 EnsureFunctionExists(M, "longjmp", I->arg_begin(), I->arg_end(), 95 Type::VoidTy); 96 break; 97 case Intrinsic::siglongjmp: 98 EnsureFunctionExists(M, "abort", I->arg_end(), I->arg_end(), 99 Type::VoidTy); 100 break; 101 case Intrinsic::memcpy: 102 M.getOrInsertFunction("memcpy", PointerType::getUnqual(Type::Int8Ty), 103 PointerType::getUnqual(Type::Int8Ty), 104 PointerType::getUnqual(Type::Int8Ty), 105 TD.getIntPtrType(), (Type *)0); 106 break; 107 case Intrinsic::memmove: 108 M.getOrInsertFunction("memmove", PointerType::getUnqual(Type::Int8Ty), 109 PointerType::getUnqual(Type::Int8Ty), 110 PointerType::getUnqual(Type::Int8Ty), 111 TD.getIntPtrType(), (Type *)0); 112 break; 113 case Intrinsic::memset: 114 M.getOrInsertFunction("memset", PointerType::getUnqual(Type::Int8Ty), 115 PointerType::getUnqual(Type::Int8Ty), 116 Type::Int32Ty, 117 TD.getIntPtrType(), (Type *)0); 118 break; 119 case Intrinsic::sqrt: 120 EnsureFPIntrinsicsExist(M, I, "sqrtf", "sqrt", "sqrtl"); 121 break; 122 case Intrinsic::sin: 123 EnsureFPIntrinsicsExist(M, I, "sinf", "sin", "sinl"); 124 break; 125 case Intrinsic::cos: 126 EnsureFPIntrinsicsExist(M, I, "cosf", "cos", "cosl"); 127 break; 128 case Intrinsic::pow: 129 EnsureFPIntrinsicsExist(M, I, "powf", "pow", "powl"); 130 break; 131 case Intrinsic::log: 132 EnsureFPIntrinsicsExist(M, I, "logf", "log", "logl"); 133 break; 134 case Intrinsic::log2: 135 EnsureFPIntrinsicsExist(M, I, "log2f", "log2", "log2l"); 136 break; 137 case Intrinsic::log10: 138 EnsureFPIntrinsicsExist(M, I, "log10f", "log10", "log10l"); 139 break; 140 case Intrinsic::exp: 141 EnsureFPIntrinsicsExist(M, I, "expf", "exp", "expl"); 142 break; 143 case Intrinsic::exp2: 144 EnsureFPIntrinsicsExist(M, I, "exp2f", "exp2", "exp2l"); 145 break; 146 } 147} 148 149/// LowerBSWAP - Emit the code to lower bswap of V before the specified 150/// instruction IP. 151static Value *LowerBSWAP(Value *V, Instruction *IP) { 152 assert(V->getType()->isInteger() && "Can't bswap a non-integer type!"); 153 154 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 155 156 IRBuilder<> Builder(IP->getParent(), IP); 157 158 switch(BitSize) { 159 default: assert(0 && "Unhandled type size of value to byteswap!"); 160 case 16: { 161 Value *Tmp1 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 8), 162 "bswap.2"); 163 Value *Tmp2 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 8), 164 "bswap.1"); 165 V = Builder.CreateOr(Tmp1, Tmp2, "bswap.i16"); 166 break; 167 } 168 case 32: { 169 Value *Tmp4 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 24), 170 "bswap.4"); 171 Value *Tmp3 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 8), 172 "bswap.3"); 173 Value *Tmp2 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 8), 174 "bswap.2"); 175 Value *Tmp1 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 24), 176 "bswap.1"); 177 Tmp3 = Builder.CreateAnd(Tmp3, ConstantInt::get(Type::Int32Ty, 0xFF0000), 178 "bswap.and3"); 179 Tmp2 = Builder.CreateAnd(Tmp2, ConstantInt::get(Type::Int32Ty, 0xFF00), 180 "bswap.and2"); 181 Tmp4 = Builder.CreateOr(Tmp4, Tmp3, "bswap.or1"); 182 Tmp2 = Builder.CreateOr(Tmp2, Tmp1, "bswap.or2"); 183 V = Builder.CreateOr(Tmp4, Tmp2, "bswap.i32"); 184 break; 185 } 186 case 64: { 187 Value *Tmp8 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 56), 188 "bswap.8"); 189 Value *Tmp7 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 40), 190 "bswap.7"); 191 Value *Tmp6 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 24), 192 "bswap.6"); 193 Value *Tmp5 = Builder.CreateShl(V, ConstantInt::get(V->getType(), 8), 194 "bswap.5"); 195 Value* Tmp4 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 8), 196 "bswap.4"); 197 Value* Tmp3 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 24), 198 "bswap.3"); 199 Value* Tmp2 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 40), 200 "bswap.2"); 201 Value* Tmp1 = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 56), 202 "bswap.1"); 203 Tmp7 = Builder.CreateAnd(Tmp7, 204 ConstantInt::get(Type::Int64Ty, 205 0xFF000000000000ULL), 206 "bswap.and7"); 207 Tmp6 = Builder.CreateAnd(Tmp6, 208 ConstantInt::get(Type::Int64Ty, 209 0xFF0000000000ULL), 210 "bswap.and6"); 211 Tmp5 = Builder.CreateAnd(Tmp5, 212 ConstantInt::get(Type::Int64Ty, 0xFF00000000ULL), 213 "bswap.and5"); 214 Tmp4 = Builder.CreateAnd(Tmp4, 215 ConstantInt::get(Type::Int64Ty, 0xFF000000ULL), 216 "bswap.and4"); 217 Tmp3 = Builder.CreateAnd(Tmp3, 218 ConstantInt::get(Type::Int64Ty, 0xFF0000ULL), 219 "bswap.and3"); 220 Tmp2 = Builder.CreateAnd(Tmp2, 221 ConstantInt::get(Type::Int64Ty, 0xFF00ULL), 222 "bswap.and2"); 223 Tmp8 = Builder.CreateOr(Tmp8, Tmp7, "bswap.or1"); 224 Tmp6 = Builder.CreateOr(Tmp6, Tmp5, "bswap.or2"); 225 Tmp4 = Builder.CreateOr(Tmp4, Tmp3, "bswap.or3"); 226 Tmp2 = Builder.CreateOr(Tmp2, Tmp1, "bswap.or4"); 227 Tmp8 = Builder.CreateOr(Tmp8, Tmp6, "bswap.or5"); 228 Tmp4 = Builder.CreateOr(Tmp4, Tmp2, "bswap.or6"); 229 V = Builder.CreateOr(Tmp8, Tmp4, "bswap.i64"); 230 break; 231 } 232 } 233 return V; 234} 235 236/// LowerCTPOP - Emit the code to lower ctpop of V before the specified 237/// instruction IP. 238static Value *LowerCTPOP(Value *V, Instruction *IP) { 239 assert(V->getType()->isInteger() && "Can't ctpop a non-integer type!"); 240 241 static const uint64_t MaskValues[6] = { 242 0x5555555555555555ULL, 0x3333333333333333ULL, 243 0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL, 244 0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL 245 }; 246 247 IRBuilder<> Builder(IP->getParent(), IP); 248 249 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 250 unsigned WordSize = (BitSize + 63) / 64; 251 Value *Count = ConstantInt::get(V->getType(), 0); 252 253 for (unsigned n = 0; n < WordSize; ++n) { 254 Value *PartValue = V; 255 for (unsigned i = 1, ct = 0; i < (BitSize>64 ? 64 : BitSize); 256 i <<= 1, ++ct) { 257 Value *MaskCst = ConstantInt::get(V->getType(), MaskValues[ct]); 258 Value *LHS = Builder.CreateAnd(PartValue, MaskCst, "cppop.and1"); 259 Value *VShift = Builder.CreateLShr(PartValue, 260 ConstantInt::get(V->getType(), i), 261 "ctpop.sh"); 262 Value *RHS = Builder.CreateAnd(VShift, MaskCst, "cppop.and2"); 263 PartValue = Builder.CreateAdd(LHS, RHS, "ctpop.step"); 264 } 265 Count = Builder.CreateAdd(PartValue, Count, "ctpop.part"); 266 if (BitSize > 64) { 267 V = Builder.CreateLShr(V, ConstantInt::get(V->getType(), 64), 268 "ctpop.part.sh"); 269 BitSize -= 64; 270 } 271 } 272 273 return Count; 274} 275 276/// LowerCTLZ - Emit the code to lower ctlz of V before the specified 277/// instruction IP. 278static Value *LowerCTLZ(Value *V, Instruction *IP) { 279 280 IRBuilder<> Builder(IP->getParent(), IP); 281 282 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 283 for (unsigned i = 1; i < BitSize; i <<= 1) { 284 Value *ShVal = ConstantInt::get(V->getType(), i); 285 ShVal = Builder.CreateLShr(V, ShVal, "ctlz.sh"); 286 V = Builder.CreateOr(V, ShVal, "ctlz.step"); 287 } 288 289 V = Builder.CreateNot(V); 290 return LowerCTPOP(V, IP); 291} 292 293/// Convert the llvm.part.select.iX.iY intrinsic. This intrinsic takes 294/// three integer arguments. The first argument is the Value from which the 295/// bits will be selected. It may be of any bit width. The second and third 296/// arguments specify a range of bits to select with the second argument 297/// specifying the low bit and the third argument specifying the high bit. Both 298/// must be type i32. The result is the corresponding selected bits from the 299/// Value in the same width as the Value (first argument). If the low bit index 300/// is higher than the high bit index then the inverse selection is done and 301/// the bits are returned in inverse order. 302/// @brief Lowering of llvm.part.select intrinsic. 303static Instruction *LowerPartSelect(CallInst *CI) { 304 IRBuilder<> Builder; 305 306 // Make sure we're dealing with a part select intrinsic here 307 Function *F = CI->getCalledFunction(); 308 const FunctionType *FT = F->getFunctionType(); 309 if (!F->isDeclaration() || !FT->getReturnType()->isInteger() || 310 FT->getNumParams() != 3 || !FT->getParamType(0)->isInteger() || 311 !FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger()) 312 return CI; 313 314 // Get the intrinsic implementation function by converting all the . to _ 315 // in the intrinsic's function name and then reconstructing the function 316 // declaration. 317 std::string Name(F->getName()); 318 for (unsigned i = 4; i < Name.length(); ++i) 319 if (Name[i] == '.') 320 Name[i] = '_'; 321 Module* M = F->getParent(); 322 F = cast<Function>(M->getOrInsertFunction(Name, FT)); 323 F->setLinkage(GlobalValue::WeakAnyLinkage); 324 325 // If we haven't defined the impl function yet, do so now 326 if (F->isDeclaration()) { 327 328 // Get the arguments to the function 329 Function::arg_iterator args = F->arg_begin(); 330 Value* Val = args++; Val->setName("Val"); 331 Value* Lo = args++; Lo->setName("Lo"); 332 Value* Hi = args++; Hi->setName("High"); 333 334 // We want to select a range of bits here such that [Hi, Lo] is shifted 335 // down to the low bits. However, it is quite possible that Hi is smaller 336 // than Lo in which case the bits have to be reversed. 337 338 // Create the blocks we will need for the two cases (forward, reverse) 339 BasicBlock* CurBB = BasicBlock::Create("entry", F); 340 BasicBlock *RevSize = BasicBlock::Create("revsize", CurBB->getParent()); 341 BasicBlock *FwdSize = BasicBlock::Create("fwdsize", CurBB->getParent()); 342 BasicBlock *Compute = BasicBlock::Create("compute", CurBB->getParent()); 343 BasicBlock *Reverse = BasicBlock::Create("reverse", CurBB->getParent()); 344 BasicBlock *RsltBlk = BasicBlock::Create("result", CurBB->getParent()); 345 346 Builder.SetInsertPoint(CurBB); 347 348 // Cast Hi and Lo to the size of Val so the widths are all the same 349 if (Hi->getType() != Val->getType()) 350 Hi = Builder.CreateIntCast(Hi, Val->getType(), /* isSigned */ false, 351 "tmp"); 352 if (Lo->getType() != Val->getType()) 353 Lo = Builder.CreateIntCast(Lo, Val->getType(), /* isSigned */ false, 354 "tmp"); 355 356 // Compute a few things that both cases will need, up front. 357 Constant* Zero = ConstantInt::get(Val->getType(), 0); 358 Constant* One = ConstantInt::get(Val->getType(), 1); 359 Constant* AllOnes = ConstantInt::getAllOnesValue(Val->getType()); 360 361 // Compare the Hi and Lo bit positions. This is used to determine 362 // which case we have (forward or reverse) 363 Value *Cmp = Builder.CreateICmpULT(Hi, Lo, "less"); 364 Builder.CreateCondBr(Cmp, RevSize, FwdSize); 365 366 // First, compute the number of bits in the forward case. 367 Builder.SetInsertPoint(FwdSize); 368 Value* FBitSize = Builder.CreateSub(Hi, Lo, "fbits"); 369 Builder.CreateBr(Compute); 370 371 // Second, compute the number of bits in the reverse case. 372 Builder.SetInsertPoint(RevSize); 373 Value* RBitSize = Builder.CreateSub(Lo, Hi, "rbits"); 374 Builder.CreateBr(Compute); 375 376 // Now, compute the bit range. Start by getting the bitsize and the shift 377 // amount (either Hi or Lo) from PHI nodes. Then we compute a mask for 378 // the number of bits we want in the range. We shift the bits down to the 379 // least significant bits, apply the mask to zero out unwanted high bits, 380 // and we have computed the "forward" result. It may still need to be 381 // reversed. 382 Builder.SetInsertPoint(Compute); 383 384 // Get the BitSize from one of the two subtractions 385 PHINode *BitSize = Builder.CreatePHI(Val->getType(), "bits"); 386 BitSize->reserveOperandSpace(2); 387 BitSize->addIncoming(FBitSize, FwdSize); 388 BitSize->addIncoming(RBitSize, RevSize); 389 390 // Get the ShiftAmount as the smaller of Hi/Lo 391 PHINode *ShiftAmt = Builder.CreatePHI(Val->getType(), "shiftamt"); 392 ShiftAmt->reserveOperandSpace(2); 393 ShiftAmt->addIncoming(Lo, FwdSize); 394 ShiftAmt->addIncoming(Hi, RevSize); 395 396 // Increment the bit size 397 Value *BitSizePlusOne = Builder.CreateAdd(BitSize, One, "bits"); 398 399 // Create a Mask to zero out the high order bits. 400 Value* Mask = Builder.CreateShl(AllOnes, BitSizePlusOne, "mask"); 401 Mask = Builder.CreateNot(Mask, "mask"); 402 403 // Shift the bits down and apply the mask 404 Value* FRes = Builder.CreateLShr(Val, ShiftAmt, "fres"); 405 FRes = Builder.CreateAnd(FRes, Mask, "fres"); 406 Builder.CreateCondBr(Cmp, Reverse, RsltBlk); 407 408 // In the Reverse block we have the mask already in FRes but we must reverse 409 // it by shifting FRes bits right and putting them in RRes by shifting them 410 // in from left. 411 Builder.SetInsertPoint(Reverse); 412 413 // First set up our loop counters 414 PHINode *Count = Builder.CreatePHI(Val->getType(), "count"); 415 Count->reserveOperandSpace(2); 416 Count->addIncoming(BitSizePlusOne, Compute); 417 418 // Next, get the value that we are shifting. 419 PHINode *BitsToShift = Builder.CreatePHI(Val->getType(), "val"); 420 BitsToShift->reserveOperandSpace(2); 421 BitsToShift->addIncoming(FRes, Compute); 422 423 // Finally, get the result of the last computation 424 PHINode *RRes = Builder.CreatePHI(Val->getType(), "rres"); 425 RRes->reserveOperandSpace(2); 426 RRes->addIncoming(Zero, Compute); 427 428 // Decrement the counter 429 Value *Decr = Builder.CreateSub(Count, One, "decr"); 430 Count->addIncoming(Decr, Reverse); 431 432 // Compute the Bit that we want to move 433 Value *Bit = Builder.CreateAnd(BitsToShift, One, "bit"); 434 435 // Compute the new value for next iteration. 436 Value *NewVal = Builder.CreateLShr(BitsToShift, One, "rshift"); 437 BitsToShift->addIncoming(NewVal, Reverse); 438 439 // Shift the bit into the low bits of the result. 440 Value *NewRes = Builder.CreateShl(RRes, One, "lshift"); 441 NewRes = Builder.CreateOr(NewRes, Bit, "addbit"); 442 RRes->addIncoming(NewRes, Reverse); 443 444 // Terminate loop if we've moved all the bits. 445 Value *Cond = Builder.CreateICmpEQ(Decr, Zero, "cond"); 446 Builder.CreateCondBr(Cond, RsltBlk, Reverse); 447 448 // Finally, in the result block, select one of the two results with a PHI 449 // node and return the result; 450 Builder.SetInsertPoint(RsltBlk); 451 PHINode *BitSelect = Builder.CreatePHI(Val->getType(), "part_select"); 452 BitSelect->reserveOperandSpace(2); 453 BitSelect->addIncoming(FRes, Compute); 454 BitSelect->addIncoming(NewRes, Reverse); 455 Builder.CreateRet(BitSelect); 456 } 457 458 // Return a call to the implementation function 459 Builder.SetInsertPoint(CI->getParent(), CI); 460 CallInst *NewCI = Builder.CreateCall3(F, CI->getOperand(1), 461 CI->getOperand(2), CI->getOperand(3)); 462 NewCI->setName(CI->getName()); 463 return NewCI; 464} 465 466/// Convert the llvm.part.set.iX.iY.iZ intrinsic. This intrinsic takes 467/// four integer arguments (iAny %Value, iAny %Replacement, i32 %Low, i32 %High) 468/// The first two arguments can be any bit width. The result is the same width 469/// as %Value. The operation replaces bits between %Low and %High with the value 470/// in %Replacement. If %Replacement is not the same width, it is truncated or 471/// zero extended as appropriate to fit the bits being replaced. If %Low is 472/// greater than %High then the inverse set of bits are replaced. 473/// @brief Lowering of llvm.bit.part.set intrinsic. 474static Instruction *LowerPartSet(CallInst *CI) { 475 IRBuilder<> Builder; 476 477 // Make sure we're dealing with a part select intrinsic here 478 Function *F = CI->getCalledFunction(); 479 const FunctionType *FT = F->getFunctionType(); 480 if (!F->isDeclaration() || !FT->getReturnType()->isInteger() || 481 FT->getNumParams() != 4 || !FT->getParamType(0)->isInteger() || 482 !FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger() || 483 !FT->getParamType(3)->isInteger()) 484 return CI; 485 486 // Get the intrinsic implementation function by converting all the . to _ 487 // in the intrinsic's function name and then reconstructing the function 488 // declaration. 489 std::string Name(F->getName()); 490 for (unsigned i = 4; i < Name.length(); ++i) 491 if (Name[i] == '.') 492 Name[i] = '_'; 493 Module* M = F->getParent(); 494 F = cast<Function>(M->getOrInsertFunction(Name, FT)); 495 F->setLinkage(GlobalValue::WeakAnyLinkage); 496 497 // If we haven't defined the impl function yet, do so now 498 if (F->isDeclaration()) { 499 // Get the arguments for the function. 500 Function::arg_iterator args = F->arg_begin(); 501 Value* Val = args++; Val->setName("Val"); 502 Value* Rep = args++; Rep->setName("Rep"); 503 Value* Lo = args++; Lo->setName("Lo"); 504 Value* Hi = args++; Hi->setName("Hi"); 505 506 // Get some types we need 507 const IntegerType* ValTy = cast<IntegerType>(Val->getType()); 508 const IntegerType* RepTy = cast<IntegerType>(Rep->getType()); 509 uint32_t RepBits = RepTy->getBitWidth(); 510 511 // Constant Definitions 512 ConstantInt* RepBitWidth = ConstantInt::get(Type::Int32Ty, RepBits); 513 ConstantInt* RepMask = ConstantInt::getAllOnesValue(RepTy); 514 ConstantInt* ValMask = ConstantInt::getAllOnesValue(ValTy); 515 ConstantInt* One = ConstantInt::get(Type::Int32Ty, 1); 516 ConstantInt* ValOne = ConstantInt::get(ValTy, 1); 517 ConstantInt* Zero = ConstantInt::get(Type::Int32Ty, 0); 518 ConstantInt* ValZero = ConstantInt::get(ValTy, 0); 519 520 // Basic blocks we fill in below. 521 BasicBlock* entry = BasicBlock::Create("entry", F, 0); 522 BasicBlock* large = BasicBlock::Create("large", F, 0); 523 BasicBlock* small = BasicBlock::Create("small", F, 0); 524 BasicBlock* reverse = BasicBlock::Create("reverse", F, 0); 525 BasicBlock* result = BasicBlock::Create("result", F, 0); 526 527 // BASIC BLOCK: entry 528 Builder.SetInsertPoint(entry); 529 // First, get the number of bits that we're placing as an i32 530 Value* is_forward = Builder.CreateICmpULT(Lo, Hi); 531 Value* Hi_pn = Builder.CreateSelect(is_forward, Hi, Lo); 532 Value* Lo_pn = Builder.CreateSelect(is_forward, Lo, Hi); 533 Value* NumBits = Builder.CreateSub(Hi_pn, Lo_pn); 534 NumBits = Builder.CreateAdd(NumBits, One); 535 // Now, convert Lo and Hi to ValTy bit width 536 Lo = Builder.CreateIntCast(Lo_pn, ValTy, /* isSigned */ false); 537 // Determine if the replacement bits are larger than the number of bits we 538 // are replacing and deal with it. 539 Value* is_large = Builder.CreateICmpULT(NumBits, RepBitWidth); 540 Builder.CreateCondBr(is_large, large, small); 541 542 // BASIC BLOCK: large 543 Builder.SetInsertPoint(large); 544 Value* MaskBits = Builder.CreateSub(RepBitWidth, NumBits); 545 MaskBits = Builder.CreateIntCast(MaskBits, RepMask->getType(), 546 /* isSigned */ false); 547 Value* Mask1 = Builder.CreateLShr(RepMask, MaskBits); 548 Value* Rep2 = Builder.CreateAnd(Mask1, Rep); 549 Builder.CreateBr(small); 550 551 // BASIC BLOCK: small 552 Builder.SetInsertPoint(small); 553 PHINode* Rep3 = Builder.CreatePHI(RepTy); 554 Rep3->reserveOperandSpace(2); 555 Rep3->addIncoming(Rep2, large); 556 Rep3->addIncoming(Rep, entry); 557 Value* Rep4 = Builder.CreateIntCast(Rep3, ValTy, /* isSigned */ false); 558 Builder.CreateCondBr(is_forward, result, reverse); 559 560 // BASIC BLOCK: reverse (reverses the bits of the replacement) 561 Builder.SetInsertPoint(reverse); 562 // Set up our loop counter as a PHI so we can decrement on each iteration. 563 // We will loop for the number of bits in the replacement value. 564 PHINode *Count = Builder.CreatePHI(Type::Int32Ty, "count"); 565 Count->reserveOperandSpace(2); 566 Count->addIncoming(NumBits, small); 567 568 // Get the value that we are shifting bits out of as a PHI because 569 // we'll change this with each iteration. 570 PHINode *BitsToShift = Builder.CreatePHI(Val->getType(), "val"); 571 BitsToShift->reserveOperandSpace(2); 572 BitsToShift->addIncoming(Rep4, small); 573 574 // Get the result of the last computation or zero on first iteration 575 PHINode *RRes = Builder.CreatePHI(Val->getType(), "rres"); 576 RRes->reserveOperandSpace(2); 577 RRes->addIncoming(ValZero, small); 578 579 // Decrement the loop counter by one 580 Value *Decr = Builder.CreateSub(Count, One); 581 Count->addIncoming(Decr, reverse); 582 583 // Get the bit that we want to move into the result 584 Value *Bit = Builder.CreateAnd(BitsToShift, ValOne); 585 586 // Compute the new value of the bits to shift for the next iteration. 587 Value *NewVal = Builder.CreateLShr(BitsToShift, ValOne); 588 BitsToShift->addIncoming(NewVal, reverse); 589 590 // Shift the bit we extracted into the low bit of the result. 591 Value *NewRes = Builder.CreateShl(RRes, ValOne); 592 NewRes = Builder.CreateOr(NewRes, Bit); 593 RRes->addIncoming(NewRes, reverse); 594 595 // Terminate loop if we've moved all the bits. 596 Value *Cond = Builder.CreateICmpEQ(Decr, Zero); 597 Builder.CreateCondBr(Cond, result, reverse); 598 599 // BASIC BLOCK: result 600 Builder.SetInsertPoint(result); 601 PHINode *Rplcmnt = Builder.CreatePHI(Val->getType()); 602 Rplcmnt->reserveOperandSpace(2); 603 Rplcmnt->addIncoming(NewRes, reverse); 604 Rplcmnt->addIncoming(Rep4, small); 605 Value* t0 = Builder.CreateIntCast(NumBits, ValTy, /* isSigned */ false); 606 Value* t1 = Builder.CreateShl(ValMask, Lo); 607 Value* t2 = Builder.CreateNot(t1); 608 Value* t3 = Builder.CreateShl(t1, t0); 609 Value* t4 = Builder.CreateOr(t2, t3); 610 Value* t5 = Builder.CreateAnd(t4, Val); 611 Value* t6 = Builder.CreateShl(Rplcmnt, Lo); 612 Value* Rslt = Builder.CreateOr(t5, t6, "part_set"); 613 Builder.CreateRet(Rslt); 614 } 615 616 // Return a call to the implementation function 617 Builder.SetInsertPoint(CI->getParent(), CI); 618 CallInst *NewCI = Builder.CreateCall4(F, CI->getOperand(1), 619 CI->getOperand(2), CI->getOperand(3), 620 CI->getOperand(4)); 621 NewCI->setName(CI->getName()); 622 return NewCI; 623} 624 625static void ReplaceFPIntrinsicWithCall(CallInst *CI, const char *Fname, 626 const char *Dname, 627 const char *LDname) { 628 switch (CI->getOperand(1)->getType()->getTypeID()) { 629 default: assert(0 && "Invalid type in intrinsic"); abort(); 630 case Type::FloatTyID: 631 ReplaceCallWith(Fname, CI, CI->op_begin() + 1, CI->op_end(), 632 Type::FloatTy); 633 break; 634 case Type::DoubleTyID: 635 ReplaceCallWith(Dname, CI, CI->op_begin() + 1, CI->op_end(), 636 Type::DoubleTy); 637 break; 638 case Type::X86_FP80TyID: 639 case Type::FP128TyID: 640 case Type::PPC_FP128TyID: 641 ReplaceCallWith(LDname, CI, CI->op_begin() + 1, CI->op_end(), 642 CI->getOperand(1)->getType()); 643 break; 644 } 645} 646 647void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) { 648 IRBuilder<> Builder(CI->getParent(), CI); 649 650 Function *Callee = CI->getCalledFunction(); 651 assert(Callee && "Cannot lower an indirect call!"); 652 653 switch (Callee->getIntrinsicID()) { 654 case Intrinsic::not_intrinsic: 655 cerr << "Cannot lower a call to a non-intrinsic function '" 656 << Callee->getName() << "'!\n"; 657 abort(); 658 default: 659 cerr << "Error: Code generator does not support intrinsic function '" 660 << Callee->getName() << "'!\n"; 661 abort(); 662 663 // The setjmp/longjmp intrinsics should only exist in the code if it was 664 // never optimized (ie, right out of the CFE), or if it has been hacked on 665 // by the lowerinvoke pass. In both cases, the right thing to do is to 666 // convert the call to an explicit setjmp or longjmp call. 667 case Intrinsic::setjmp: { 668 Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin() + 1, CI->op_end(), 669 Type::Int32Ty); 670 if (CI->getType() != Type::VoidTy) 671 CI->replaceAllUsesWith(V); 672 break; 673 } 674 case Intrinsic::sigsetjmp: 675 if (CI->getType() != Type::VoidTy) 676 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 677 break; 678 679 case Intrinsic::longjmp: { 680 ReplaceCallWith("longjmp", CI, CI->op_begin() + 1, CI->op_end(), 681 Type::VoidTy); 682 break; 683 } 684 685 case Intrinsic::siglongjmp: { 686 // Insert the call to abort 687 ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(), 688 Type::VoidTy); 689 break; 690 } 691 case Intrinsic::ctpop: 692 CI->replaceAllUsesWith(LowerCTPOP(CI->getOperand(1), CI)); 693 break; 694 695 case Intrinsic::bswap: 696 CI->replaceAllUsesWith(LowerBSWAP(CI->getOperand(1), CI)); 697 break; 698 699 case Intrinsic::ctlz: 700 CI->replaceAllUsesWith(LowerCTLZ(CI->getOperand(1), CI)); 701 break; 702 703 case Intrinsic::cttz: { 704 // cttz(x) -> ctpop(~X & (X-1)) 705 Value *Src = CI->getOperand(1); 706 Value *NotSrc = Builder.CreateNot(Src); 707 NotSrc->setName(Src->getName() + ".not"); 708 Value *SrcM1 = ConstantInt::get(Src->getType(), 1); 709 SrcM1 = Builder.CreateSub(Src, SrcM1); 710 Src = LowerCTPOP(Builder.CreateAnd(NotSrc, SrcM1), CI); 711 CI->replaceAllUsesWith(Src); 712 break; 713 } 714 715 case Intrinsic::part_select: 716 CI->replaceAllUsesWith(LowerPartSelect(CI)); 717 break; 718 719 case Intrinsic::part_set: 720 CI->replaceAllUsesWith(LowerPartSet(CI)); 721 break; 722 723 case Intrinsic::stacksave: 724 case Intrinsic::stackrestore: { 725 if (!Warned) 726 cerr << "WARNING: this target does not support the llvm.stack" 727 << (Callee->getIntrinsicID() == Intrinsic::stacksave ? 728 "save" : "restore") << " intrinsic.\n"; 729 Warned = true; 730 if (Callee->getIntrinsicID() == Intrinsic::stacksave) 731 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 732 break; 733 } 734 735 case Intrinsic::returnaddress: 736 case Intrinsic::frameaddress: 737 cerr << "WARNING: this target does not support the llvm." 738 << (Callee->getIntrinsicID() == Intrinsic::returnaddress ? 739 "return" : "frame") << "address intrinsic.\n"; 740 CI->replaceAllUsesWith(ConstantPointerNull::get( 741 cast<PointerType>(CI->getType()))); 742 break; 743 744 case Intrinsic::prefetch: 745 break; // Simply strip out prefetches on unsupported architectures 746 747 case Intrinsic::pcmarker: 748 break; // Simply strip out pcmarker on unsupported architectures 749 case Intrinsic::readcyclecounter: { 750 cerr << "WARNING: this target does not support the llvm.readcyclecoun" 751 << "ter intrinsic. It is being lowered to a constant 0\n"; 752 CI->replaceAllUsesWith(ConstantInt::get(Type::Int64Ty, 0)); 753 break; 754 } 755 756 case Intrinsic::dbg_stoppoint: 757 case Intrinsic::dbg_region_start: 758 case Intrinsic::dbg_region_end: 759 case Intrinsic::dbg_func_start: 760 case Intrinsic::dbg_declare: 761 break; // Simply strip out debugging intrinsics 762 763 case Intrinsic::eh_exception: 764 case Intrinsic::eh_selector_i32: 765 case Intrinsic::eh_selector_i64: 766 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 767 break; 768 769 case Intrinsic::eh_typeid_for_i32: 770 case Intrinsic::eh_typeid_for_i64: 771 // Return something different to eh_selector. 772 CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1)); 773 break; 774 775 case Intrinsic::var_annotation: 776 break; // Strip out annotate intrinsic 777 778 case Intrinsic::memcpy: { 779 const IntegerType *IntPtr = TD.getIntPtrType(); 780 Value *Size = Builder.CreateIntCast(CI->getOperand(3), IntPtr, 781 /* isSigned */ false); 782 Value *Ops[3]; 783 Ops[0] = CI->getOperand(1); 784 Ops[1] = CI->getOperand(2); 785 Ops[2] = Size; 786 ReplaceCallWith("memcpy", CI, Ops, Ops+3, CI->getOperand(1)->getType()); 787 break; 788 } 789 case Intrinsic::memmove: { 790 const IntegerType *IntPtr = TD.getIntPtrType(); 791 Value *Size = Builder.CreateIntCast(CI->getOperand(3), IntPtr, 792 /* isSigned */ false); 793 Value *Ops[3]; 794 Ops[0] = CI->getOperand(1); 795 Ops[1] = CI->getOperand(2); 796 Ops[2] = Size; 797 ReplaceCallWith("memmove", CI, Ops, Ops+3, CI->getOperand(1)->getType()); 798 break; 799 } 800 case Intrinsic::memset: { 801 const IntegerType *IntPtr = TD.getIntPtrType(); 802 Value *Size = Builder.CreateIntCast(CI->getOperand(3), IntPtr, 803 /* isSigned */ false); 804 Value *Ops[3]; 805 Ops[0] = CI->getOperand(1); 806 // Extend the amount to i32. 807 Ops[1] = Builder.CreateIntCast(CI->getOperand(2), Type::Int32Ty, 808 /* isSigned */ false); 809 Ops[2] = Size; 810 ReplaceCallWith("memset", CI, Ops, Ops+3, CI->getOperand(1)->getType()); 811 break; 812 } 813 case Intrinsic::sqrt: { 814 ReplaceFPIntrinsicWithCall(CI, "sqrtf", "sqrt", "sqrtl"); 815 break; 816 } 817 case Intrinsic::log: { 818 ReplaceFPIntrinsicWithCall(CI, "logf", "log", "logl"); 819 break; 820 } 821 case Intrinsic::log2: { 822 ReplaceFPIntrinsicWithCall(CI, "log2f", "log2", "log2l"); 823 break; 824 } 825 case Intrinsic::log10: { 826 ReplaceFPIntrinsicWithCall(CI, "log10f", "log10", "log10l"); 827 break; 828 } 829 case Intrinsic::exp: { 830 ReplaceFPIntrinsicWithCall(CI, "expf", "exp", "expl"); 831 break; 832 } 833 case Intrinsic::exp2: { 834 ReplaceFPIntrinsicWithCall(CI, "exp2f", "exp2", "exp2l"); 835 break; 836 } 837 case Intrinsic::pow: { 838 ReplaceFPIntrinsicWithCall(CI, "powf", "pow", "powl"); 839 break; 840 } 841 case Intrinsic::flt_rounds: 842 // Lower to "round to the nearest" 843 if (CI->getType() != Type::VoidTy) 844 CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1)); 845 break; 846 } 847 848 assert(CI->use_empty() && 849 "Lowering should have eliminated any uses of the intrinsic call!"); 850 CI->eraseFromParent(); 851} 852