IntrinsicLowering.cpp revision 824b958e6fb1236e92e4d07f3acf18fca107cdc0
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/Instructions.h" 18#include "llvm/Type.h" 19#include "llvm/CodeGen/IntrinsicLowering.h" 20#include "llvm/Support/Streams.h" 21#include "llvm/Target/TargetData.h" 22#include "llvm/ADT/SmallVector.h" 23#include "llvm/ADT/STLExtras.h" 24using namespace llvm; 25 26template <class ArgIt> 27static void EnsureFunctionExists(Module &M, const char *Name, 28 ArgIt ArgBegin, ArgIt ArgEnd, 29 const Type *RetTy) { 30 // Insert a correctly-typed definition now. 31 std::vector<const Type *> ParamTys; 32 for (ArgIt I = ArgBegin; I != ArgEnd; ++I) 33 ParamTys.push_back(I->getType()); 34 M.getOrInsertFunction(Name, FunctionType::get(RetTy, ParamTys, false)); 35} 36 37static void EnsureFPIntrinsicsExist(Module &M, Module::iterator I, 38 const char *FName, 39 const char *DName, const char *LDName) { 40 // Insert definitions for all the floating point types. 41 switch((int)I->arg_begin()->getType()->getTypeID()) { 42 case Type::FloatTyID: 43 EnsureFunctionExists(M, FName, I->arg_begin(), I->arg_end(), 44 Type::FloatTy); 45 case Type::DoubleTyID: 46 EnsureFunctionExists(M, DName, I->arg_begin(), I->arg_end(), 47 Type::DoubleTy); 48 case Type::X86_FP80TyID: 49 case Type::FP128TyID: 50 case Type::PPC_FP128TyID: 51 EnsureFunctionExists(M, LDName, I->arg_begin(), I->arg_end(), 52 I->arg_begin()->getType()); 53 } 54} 55 56/// ReplaceCallWith - This function is used when we want to lower an intrinsic 57/// call to a call of an external function. This handles hard cases such as 58/// when there was already a prototype for the external function, and if that 59/// prototype doesn't match the arguments we expect to pass in. 60template <class ArgIt> 61static CallInst *ReplaceCallWith(const char *NewFn, CallInst *CI, 62 ArgIt ArgBegin, ArgIt ArgEnd, 63 const Type *RetTy, Constant *&FCache) { 64 if (!FCache) { 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 FCache = M->getOrInsertFunction(NewFn, 73 FunctionType::get(RetTy, ParamTys, false)); 74 } 75 76 SmallVector<Value *, 8> Args(ArgBegin, ArgEnd); 77 CallInst *NewCI = CallInst::Create(FCache, Args.begin(), Args.end(), 78 CI->getName(), CI); 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 switch(BitSize) { 157 default: assert(0 && "Unhandled type size of value to byteswap!"); 158 case 16: { 159 Value *Tmp1 = BinaryOperator::CreateShl(V, 160 ConstantInt::get(V->getType(),8),"bswap.2",IP); 161 Value *Tmp2 = BinaryOperator::CreateLShr(V, 162 ConstantInt::get(V->getType(),8),"bswap.1",IP); 163 V = BinaryOperator::CreateOr(Tmp1, Tmp2, "bswap.i16", IP); 164 break; 165 } 166 case 32: { 167 Value *Tmp4 = BinaryOperator::CreateShl(V, 168 ConstantInt::get(V->getType(),24),"bswap.4", IP); 169 Value *Tmp3 = BinaryOperator::CreateShl(V, 170 ConstantInt::get(V->getType(),8),"bswap.3",IP); 171 Value *Tmp2 = BinaryOperator::CreateLShr(V, 172 ConstantInt::get(V->getType(),8),"bswap.2",IP); 173 Value *Tmp1 = BinaryOperator::CreateLShr(V, 174 ConstantInt::get(V->getType(),24),"bswap.1", IP); 175 Tmp3 = BinaryOperator::CreateAnd(Tmp3, 176 ConstantInt::get(Type::Int32Ty, 0xFF0000), 177 "bswap.and3", IP); 178 Tmp2 = BinaryOperator::CreateAnd(Tmp2, 179 ConstantInt::get(Type::Int32Ty, 0xFF00), 180 "bswap.and2", IP); 181 Tmp4 = BinaryOperator::CreateOr(Tmp4, Tmp3, "bswap.or1", IP); 182 Tmp2 = BinaryOperator::CreateOr(Tmp2, Tmp1, "bswap.or2", IP); 183 V = BinaryOperator::CreateOr(Tmp4, Tmp2, "bswap.i32", IP); 184 break; 185 } 186 case 64: { 187 Value *Tmp8 = BinaryOperator::CreateShl(V, 188 ConstantInt::get(V->getType(),56),"bswap.8", IP); 189 Value *Tmp7 = BinaryOperator::CreateShl(V, 190 ConstantInt::get(V->getType(),40),"bswap.7", IP); 191 Value *Tmp6 = BinaryOperator::CreateShl(V, 192 ConstantInt::get(V->getType(),24),"bswap.6", IP); 193 Value *Tmp5 = BinaryOperator::CreateShl(V, 194 ConstantInt::get(V->getType(),8),"bswap.5", IP); 195 Value* Tmp4 = BinaryOperator::CreateLShr(V, 196 ConstantInt::get(V->getType(),8),"bswap.4", IP); 197 Value* Tmp3 = BinaryOperator::CreateLShr(V, 198 ConstantInt::get(V->getType(),24),"bswap.3", IP); 199 Value* Tmp2 = BinaryOperator::CreateLShr(V, 200 ConstantInt::get(V->getType(),40),"bswap.2", IP); 201 Value* Tmp1 = BinaryOperator::CreateLShr(V, 202 ConstantInt::get(V->getType(),56),"bswap.1", IP); 203 Tmp7 = BinaryOperator::CreateAnd(Tmp7, 204 ConstantInt::get(Type::Int64Ty, 205 0xFF000000000000ULL), 206 "bswap.and7", IP); 207 Tmp6 = BinaryOperator::CreateAnd(Tmp6, 208 ConstantInt::get(Type::Int64Ty, 0xFF0000000000ULL), 209 "bswap.and6", IP); 210 Tmp5 = BinaryOperator::CreateAnd(Tmp5, 211 ConstantInt::get(Type::Int64Ty, 0xFF00000000ULL), 212 "bswap.and5", IP); 213 Tmp4 = BinaryOperator::CreateAnd(Tmp4, 214 ConstantInt::get(Type::Int64Ty, 0xFF000000ULL), 215 "bswap.and4", IP); 216 Tmp3 = BinaryOperator::CreateAnd(Tmp3, 217 ConstantInt::get(Type::Int64Ty, 0xFF0000ULL), 218 "bswap.and3", IP); 219 Tmp2 = BinaryOperator::CreateAnd(Tmp2, 220 ConstantInt::get(Type::Int64Ty, 0xFF00ULL), 221 "bswap.and2", IP); 222 Tmp8 = BinaryOperator::CreateOr(Tmp8, Tmp7, "bswap.or1", IP); 223 Tmp6 = BinaryOperator::CreateOr(Tmp6, Tmp5, "bswap.or2", IP); 224 Tmp4 = BinaryOperator::CreateOr(Tmp4, Tmp3, "bswap.or3", IP); 225 Tmp2 = BinaryOperator::CreateOr(Tmp2, Tmp1, "bswap.or4", IP); 226 Tmp8 = BinaryOperator::CreateOr(Tmp8, Tmp6, "bswap.or5", IP); 227 Tmp4 = BinaryOperator::CreateOr(Tmp4, Tmp2, "bswap.or6", IP); 228 V = BinaryOperator::CreateOr(Tmp8, Tmp4, "bswap.i64", IP); 229 break; 230 } 231 } 232 return V; 233} 234 235/// LowerCTPOP - Emit the code to lower ctpop of V before the specified 236/// instruction IP. 237static Value *LowerCTPOP(Value *V, Instruction *IP) { 238 assert(V->getType()->isInteger() && "Can't ctpop a non-integer type!"); 239 240 static const uint64_t MaskValues[6] = { 241 0x5555555555555555ULL, 0x3333333333333333ULL, 242 0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL, 243 0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL 244 }; 245 246 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 247 unsigned WordSize = (BitSize + 63) / 64; 248 Value *Count = ConstantInt::get(V->getType(), 0); 249 250 for (unsigned n = 0; n < WordSize; ++n) { 251 Value *PartValue = V; 252 for (unsigned i = 1, ct = 0; i < (BitSize>64 ? 64 : BitSize); 253 i <<= 1, ++ct) { 254 Value *MaskCst = ConstantInt::get(V->getType(), MaskValues[ct]); 255 Value *LHS = BinaryOperator::CreateAnd( 256 PartValue, MaskCst, "cppop.and1", IP); 257 Value *VShift = BinaryOperator::CreateLShr(PartValue, 258 ConstantInt::get(V->getType(), i), "ctpop.sh", IP); 259 Value *RHS = BinaryOperator::CreateAnd(VShift, MaskCst, "cppop.and2", IP); 260 PartValue = BinaryOperator::CreateAdd(LHS, RHS, "ctpop.step", IP); 261 } 262 Count = BinaryOperator::CreateAdd(PartValue, Count, "ctpop.part", IP); 263 if (BitSize > 64) { 264 V = BinaryOperator::CreateLShr(V, ConstantInt::get(V->getType(), 64), 265 "ctpop.part.sh", IP); 266 BitSize -= 64; 267 } 268 } 269 270 return Count; 271} 272 273/// LowerCTLZ - Emit the code to lower ctlz of V before the specified 274/// instruction IP. 275static Value *LowerCTLZ(Value *V, Instruction *IP) { 276 277 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 278 for (unsigned i = 1; i < BitSize; i <<= 1) { 279 Value *ShVal = ConstantInt::get(V->getType(), i); 280 ShVal = BinaryOperator::CreateLShr(V, ShVal, "ctlz.sh", IP); 281 V = BinaryOperator::CreateOr(V, ShVal, "ctlz.step", IP); 282 } 283 284 V = BinaryOperator::CreateNot(V, "", IP); 285 return LowerCTPOP(V, IP); 286} 287 288/// Convert the llvm.part.select.iX.iY intrinsic. This intrinsic takes 289/// three integer arguments. The first argument is the Value from which the 290/// bits will be selected. It may be of any bit width. The second and third 291/// arguments specify a range of bits to select with the second argument 292/// specifying the low bit and the third argument specifying the high bit. Both 293/// must be type i32. The result is the corresponding selected bits from the 294/// Value in the same width as the Value (first argument). If the low bit index 295/// is higher than the high bit index then the inverse selection is done and 296/// the bits are returned in inverse order. 297/// @brief Lowering of llvm.part.select intrinsic. 298static Instruction *LowerPartSelect(CallInst *CI) { 299 // Make sure we're dealing with a part select intrinsic here 300 Function *F = CI->getCalledFunction(); 301 const FunctionType *FT = F->getFunctionType(); 302 if (!F->isDeclaration() || !FT->getReturnType()->isInteger() || 303 FT->getNumParams() != 3 || !FT->getParamType(0)->isInteger() || 304 !FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger()) 305 return CI; 306 307 // Get the intrinsic implementation function by converting all the . to _ 308 // in the intrinsic's function name and then reconstructing the function 309 // declaration. 310 std::string Name(F->getName()); 311 for (unsigned i = 4; i < Name.length(); ++i) 312 if (Name[i] == '.') 313 Name[i] = '_'; 314 Module* M = F->getParent(); 315 F = cast<Function>(M->getOrInsertFunction(Name, FT)); 316 F->setLinkage(GlobalValue::WeakLinkage); 317 318 // If we haven't defined the impl function yet, do so now 319 if (F->isDeclaration()) { 320 321 // Get the arguments to the function 322 Function::arg_iterator args = F->arg_begin(); 323 Value* Val = args++; Val->setName("Val"); 324 Value* Lo = args++; Lo->setName("Lo"); 325 Value* Hi = args++; Hi->setName("High"); 326 327 // We want to select a range of bits here such that [Hi, Lo] is shifted 328 // down to the low bits. However, it is quite possible that Hi is smaller 329 // than Lo in which case the bits have to be reversed. 330 331 // Create the blocks we will need for the two cases (forward, reverse) 332 BasicBlock* CurBB = BasicBlock::Create("entry", F); 333 BasicBlock *RevSize = BasicBlock::Create("revsize", CurBB->getParent()); 334 BasicBlock *FwdSize = BasicBlock::Create("fwdsize", CurBB->getParent()); 335 BasicBlock *Compute = BasicBlock::Create("compute", CurBB->getParent()); 336 BasicBlock *Reverse = BasicBlock::Create("reverse", CurBB->getParent()); 337 BasicBlock *RsltBlk = BasicBlock::Create("result", CurBB->getParent()); 338 339 // Cast Hi and Lo to the size of Val so the widths are all the same 340 if (Hi->getType() != Val->getType()) 341 Hi = CastInst::CreateIntegerCast(Hi, Val->getType(), false, 342 "tmp", CurBB); 343 if (Lo->getType() != Val->getType()) 344 Lo = CastInst::CreateIntegerCast(Lo, Val->getType(), false, 345 "tmp", CurBB); 346 347 // Compute a few things that both cases will need, up front. 348 Constant* Zero = ConstantInt::get(Val->getType(), 0); 349 Constant* One = ConstantInt::get(Val->getType(), 1); 350 Constant* AllOnes = ConstantInt::getAllOnesValue(Val->getType()); 351 352 // Compare the Hi and Lo bit positions. This is used to determine 353 // which case we have (forward or reverse) 354 ICmpInst *Cmp = new ICmpInst(ICmpInst::ICMP_ULT, Hi, Lo, "less",CurBB); 355 BranchInst::Create(RevSize, FwdSize, Cmp, CurBB); 356 357 // First, copmute the number of bits in the forward case. 358 Instruction* FBitSize = 359 BinaryOperator::CreateSub(Hi, Lo,"fbits", FwdSize); 360 BranchInst::Create(Compute, FwdSize); 361 362 // Second, compute the number of bits in the reverse case. 363 Instruction* RBitSize = 364 BinaryOperator::CreateSub(Lo, Hi, "rbits", RevSize); 365 BranchInst::Create(Compute, RevSize); 366 367 // Now, compute the bit range. Start by getting the bitsize and the shift 368 // amount (either Hi or Lo) from PHI nodes. Then we compute a mask for 369 // the number of bits we want in the range. We shift the bits down to the 370 // least significant bits, apply the mask to zero out unwanted high bits, 371 // and we have computed the "forward" result. It may still need to be 372 // reversed. 373 374 // Get the BitSize from one of the two subtractions 375 PHINode *BitSize = PHINode::Create(Val->getType(), "bits", Compute); 376 BitSize->reserveOperandSpace(2); 377 BitSize->addIncoming(FBitSize, FwdSize); 378 BitSize->addIncoming(RBitSize, RevSize); 379 380 // Get the ShiftAmount as the smaller of Hi/Lo 381 PHINode *ShiftAmt = PHINode::Create(Val->getType(), "shiftamt", Compute); 382 ShiftAmt->reserveOperandSpace(2); 383 ShiftAmt->addIncoming(Lo, FwdSize); 384 ShiftAmt->addIncoming(Hi, RevSize); 385 386 // Increment the bit size 387 Instruction *BitSizePlusOne = 388 BinaryOperator::CreateAdd(BitSize, One, "bits", Compute); 389 390 // Create a Mask to zero out the high order bits. 391 Instruction* Mask = 392 BinaryOperator::CreateShl(AllOnes, BitSizePlusOne, "mask", Compute); 393 Mask = BinaryOperator::CreateNot(Mask, "mask", Compute); 394 395 // Shift the bits down and apply the mask 396 Instruction* FRes = 397 BinaryOperator::CreateLShr(Val, ShiftAmt, "fres", Compute); 398 FRes = BinaryOperator::CreateAnd(FRes, Mask, "fres", Compute); 399 BranchInst::Create(Reverse, RsltBlk, Cmp, Compute); 400 401 // In the Reverse block we have the mask already in FRes but we must reverse 402 // it by shifting FRes bits right and putting them in RRes by shifting them 403 // in from left. 404 405 // First set up our loop counters 406 PHINode *Count = PHINode::Create(Val->getType(), "count", Reverse); 407 Count->reserveOperandSpace(2); 408 Count->addIncoming(BitSizePlusOne, Compute); 409 410 // Next, get the value that we are shifting. 411 PHINode *BitsToShift = PHINode::Create(Val->getType(), "val", Reverse); 412 BitsToShift->reserveOperandSpace(2); 413 BitsToShift->addIncoming(FRes, Compute); 414 415 // Finally, get the result of the last computation 416 PHINode *RRes = PHINode::Create(Val->getType(), "rres", Reverse); 417 RRes->reserveOperandSpace(2); 418 RRes->addIncoming(Zero, Compute); 419 420 // Decrement the counter 421 Instruction *Decr = BinaryOperator::CreateSub(Count, One, "decr", Reverse); 422 Count->addIncoming(Decr, Reverse); 423 424 // Compute the Bit that we want to move 425 Instruction *Bit = 426 BinaryOperator::CreateAnd(BitsToShift, One, "bit", Reverse); 427 428 // Compute the new value for next iteration. 429 Instruction *NewVal = 430 BinaryOperator::CreateLShr(BitsToShift, One, "rshift", Reverse); 431 BitsToShift->addIncoming(NewVal, Reverse); 432 433 // Shift the bit into the low bits of the result. 434 Instruction *NewRes = 435 BinaryOperator::CreateShl(RRes, One, "lshift", Reverse); 436 NewRes = BinaryOperator::CreateOr(NewRes, Bit, "addbit", Reverse); 437 RRes->addIncoming(NewRes, Reverse); 438 439 // Terminate loop if we've moved all the bits. 440 ICmpInst *Cond = 441 new ICmpInst(ICmpInst::ICMP_EQ, Decr, Zero, "cond", Reverse); 442 BranchInst::Create(RsltBlk, Reverse, Cond, Reverse); 443 444 // Finally, in the result block, select one of the two results with a PHI 445 // node and return the result; 446 CurBB = RsltBlk; 447 PHINode *BitSelect = PHINode::Create(Val->getType(), "part_select", CurBB); 448 BitSelect->reserveOperandSpace(2); 449 BitSelect->addIncoming(FRes, Compute); 450 BitSelect->addIncoming(NewRes, Reverse); 451 ReturnInst::Create(BitSelect, CurBB); 452 } 453 454 // Return a call to the implementation function 455 Value *Args[] = { 456 CI->getOperand(1), 457 CI->getOperand(2), 458 CI->getOperand(3) 459 }; 460 return CallInst::Create(F, Args, array_endof(Args), CI->getName(), CI); 461} 462 463/// Convert the llvm.part.set.iX.iY.iZ intrinsic. This intrinsic takes 464/// four integer arguments (iAny %Value, iAny %Replacement, i32 %Low, i32 %High) 465/// The first two arguments can be any bit width. The result is the same width 466/// as %Value. The operation replaces bits between %Low and %High with the value 467/// in %Replacement. If %Replacement is not the same width, it is truncated or 468/// zero extended as appropriate to fit the bits being replaced. If %Low is 469/// greater than %High then the inverse set of bits are replaced. 470/// @brief Lowering of llvm.bit.part.set intrinsic. 471static Instruction *LowerPartSet(CallInst *CI) { 472 // Make sure we're dealing with a part select intrinsic here 473 Function *F = CI->getCalledFunction(); 474 const FunctionType *FT = F->getFunctionType(); 475 if (!F->isDeclaration() || !FT->getReturnType()->isInteger() || 476 FT->getNumParams() != 4 || !FT->getParamType(0)->isInteger() || 477 !FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger() || 478 !FT->getParamType(3)->isInteger()) 479 return CI; 480 481 // Get the intrinsic implementation function by converting all the . to _ 482 // in the intrinsic's function name and then reconstructing the function 483 // declaration. 484 std::string Name(F->getName()); 485 for (unsigned i = 4; i < Name.length(); ++i) 486 if (Name[i] == '.') 487 Name[i] = '_'; 488 Module* M = F->getParent(); 489 F = cast<Function>(M->getOrInsertFunction(Name, FT)); 490 F->setLinkage(GlobalValue::WeakLinkage); 491 492 // If we haven't defined the impl function yet, do so now 493 if (F->isDeclaration()) { 494 // Get the arguments for the function. 495 Function::arg_iterator args = F->arg_begin(); 496 Value* Val = args++; Val->setName("Val"); 497 Value* Rep = args++; Rep->setName("Rep"); 498 Value* Lo = args++; Lo->setName("Lo"); 499 Value* Hi = args++; Hi->setName("Hi"); 500 501 // Get some types we need 502 const IntegerType* ValTy = cast<IntegerType>(Val->getType()); 503 const IntegerType* RepTy = cast<IntegerType>(Rep->getType()); 504 uint32_t ValBits = ValTy->getBitWidth(); 505 uint32_t RepBits = RepTy->getBitWidth(); 506 507 // Constant Definitions 508 ConstantInt* RepBitWidth = ConstantInt::get(Type::Int32Ty, RepBits); 509 ConstantInt* RepMask = ConstantInt::getAllOnesValue(RepTy); 510 ConstantInt* ValMask = ConstantInt::getAllOnesValue(ValTy); 511 ConstantInt* One = ConstantInt::get(Type::Int32Ty, 1); 512 ConstantInt* ValOne = ConstantInt::get(ValTy, 1); 513 ConstantInt* Zero = ConstantInt::get(Type::Int32Ty, 0); 514 ConstantInt* ValZero = ConstantInt::get(ValTy, 0); 515 516 // Basic blocks we fill in below. 517 BasicBlock* entry = BasicBlock::Create("entry", F, 0); 518 BasicBlock* large = BasicBlock::Create("large", F, 0); 519 BasicBlock* small = BasicBlock::Create("small", F, 0); 520 BasicBlock* reverse = BasicBlock::Create("reverse", F, 0); 521 BasicBlock* result = BasicBlock::Create("result", F, 0); 522 523 // BASIC BLOCK: entry 524 // First, get the number of bits that we're placing as an i32 525 ICmpInst* is_forward = 526 new ICmpInst(ICmpInst::ICMP_ULT, Lo, Hi, "", entry); 527 SelectInst* Hi_pn = SelectInst::Create(is_forward, Hi, Lo, "", entry); 528 SelectInst* Lo_pn = SelectInst::Create(is_forward, Lo, Hi, "", entry); 529 BinaryOperator* NumBits = BinaryOperator::CreateSub(Hi_pn, Lo_pn, "",entry); 530 NumBits = BinaryOperator::CreateAdd(NumBits, One, "", entry); 531 // Now, convert Lo and Hi to ValTy bit width 532 if (ValBits > 32) { 533 Lo = new ZExtInst(Lo_pn, ValTy, "", entry); 534 } else if (ValBits < 32) { 535 Lo = new TruncInst(Lo_pn, ValTy, "", entry); 536 } 537 // Determine if the replacement bits are larger than the number of bits we 538 // are replacing and deal with it. 539 ICmpInst* is_large = 540 new ICmpInst(ICmpInst::ICMP_ULT, NumBits, RepBitWidth, "", entry); 541 BranchInst::Create(large, small, is_large, entry); 542 543 // BASIC BLOCK: large 544 Instruction* MaskBits = 545 BinaryOperator::CreateSub(RepBitWidth, NumBits, "", large); 546 MaskBits = CastInst::CreateIntegerCast(MaskBits, RepMask->getType(), 547 false, "", large); 548 BinaryOperator* Mask1 = 549 BinaryOperator::CreateLShr(RepMask, MaskBits, "", large); 550 BinaryOperator* Rep2 = BinaryOperator::CreateAnd(Mask1, Rep, "", large); 551 BranchInst::Create(small, large); 552 553 // BASIC BLOCK: small 554 PHINode* Rep3 = PHINode::Create(RepTy, "", small); 555 Rep3->reserveOperandSpace(2); 556 Rep3->addIncoming(Rep2, large); 557 Rep3->addIncoming(Rep, entry); 558 Value* Rep4 = Rep3; 559 if (ValBits > RepBits) 560 Rep4 = new ZExtInst(Rep3, ValTy, "", small); 561 else if (ValBits < RepBits) 562 Rep4 = new TruncInst(Rep3, ValTy, "", small); 563 BranchInst::Create(result, reverse, is_forward, small); 564 565 // BASIC BLOCK: reverse (reverses the bits of the replacement) 566 // Set up our loop counter as a PHI so we can decrement on each iteration. 567 // We will loop for the number of bits in the replacement value. 568 PHINode *Count = PHINode::Create(Type::Int32Ty, "count", reverse); 569 Count->reserveOperandSpace(2); 570 Count->addIncoming(NumBits, small); 571 572 // Get the value that we are shifting bits out of as a PHI because 573 // we'll change this with each iteration. 574 PHINode *BitsToShift = PHINode::Create(Val->getType(), "val", reverse); 575 BitsToShift->reserveOperandSpace(2); 576 BitsToShift->addIncoming(Rep4, small); 577 578 // Get the result of the last computation or zero on first iteration 579 PHINode *RRes = PHINode::Create(Val->getType(), "rres", reverse); 580 RRes->reserveOperandSpace(2); 581 RRes->addIncoming(ValZero, small); 582 583 // Decrement the loop counter by one 584 Instruction *Decr = BinaryOperator::CreateSub(Count, One, "", reverse); 585 Count->addIncoming(Decr, reverse); 586 587 // Get the bit that we want to move into the result 588 Value *Bit = BinaryOperator::CreateAnd(BitsToShift, ValOne, "", reverse); 589 590 // Compute the new value of the bits to shift for the next iteration. 591 Value *NewVal = BinaryOperator::CreateLShr(BitsToShift, ValOne,"", reverse); 592 BitsToShift->addIncoming(NewVal, reverse); 593 594 // Shift the bit we extracted into the low bit of the result. 595 Instruction *NewRes = BinaryOperator::CreateShl(RRes, ValOne, "", reverse); 596 NewRes = BinaryOperator::CreateOr(NewRes, Bit, "", reverse); 597 RRes->addIncoming(NewRes, reverse); 598 599 // Terminate loop if we've moved all the bits. 600 ICmpInst *Cond = new ICmpInst(ICmpInst::ICMP_EQ, Decr, Zero, "", reverse); 601 BranchInst::Create(result, reverse, Cond, reverse); 602 603 // BASIC BLOCK: result 604 PHINode *Rplcmnt = PHINode::Create(Val->getType(), "", result); 605 Rplcmnt->reserveOperandSpace(2); 606 Rplcmnt->addIncoming(NewRes, reverse); 607 Rplcmnt->addIncoming(Rep4, small); 608 Value* t0 = CastInst::CreateIntegerCast(NumBits,ValTy,false,"",result); 609 Value* t1 = BinaryOperator::CreateShl(ValMask, Lo, "", result); 610 Value* t2 = BinaryOperator::CreateNot(t1, "", result); 611 Value* t3 = BinaryOperator::CreateShl(t1, t0, "", result); 612 Value* t4 = BinaryOperator::CreateOr(t2, t3, "", result); 613 Value* t5 = BinaryOperator::CreateAnd(t4, Val, "", result); 614 Value* t6 = BinaryOperator::CreateShl(Rplcmnt, Lo, "", result); 615 Value* Rslt = BinaryOperator::CreateOr(t5, t6, "part_set", result); 616 ReturnInst::Create(Rslt, result); 617 } 618 619 // Return a call to the implementation function 620 Value *Args[] = { 621 CI->getOperand(1), 622 CI->getOperand(2), 623 CI->getOperand(3), 624 CI->getOperand(4) 625 }; 626 return CallInst::Create(F, Args, array_endof(Args), CI->getName(), CI); 627} 628 629static void ReplaceFPIntrinsicWithCall(CallInst *CI, Constant *FCache, 630 Constant *DCache, Constant *LDCache, 631 const char *Fname, const char *Dname, 632 const char *LDname) { 633 switch (CI->getOperand(1)->getType()->getTypeID()) { 634 default: assert(0 && "Invalid type in intrinsic"); abort(); 635 case Type::FloatTyID: 636 ReplaceCallWith(Fname, CI, CI->op_begin()+1, CI->op_end(), 637 Type::FloatTy, FCache); 638 break; 639 case Type::DoubleTyID: 640 ReplaceCallWith(Dname, CI, CI->op_begin()+1, CI->op_end(), 641 Type::DoubleTy, DCache); 642 break; 643 case Type::X86_FP80TyID: 644 case Type::FP128TyID: 645 case Type::PPC_FP128TyID: 646 ReplaceCallWith(LDname, CI, CI->op_begin()+1, CI->op_end(), 647 CI->getOperand(1)->getType(), LDCache); 648 break; 649 } 650} 651 652void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) { 653 Function *Callee = CI->getCalledFunction(); 654 assert(Callee && "Cannot lower an indirect call!"); 655 656 switch (Callee->getIntrinsicID()) { 657 case Intrinsic::not_intrinsic: 658 cerr << "Cannot lower a call to a non-intrinsic function '" 659 << Callee->getName() << "'!\n"; 660 abort(); 661 default: 662 cerr << "Error: Code generator does not support intrinsic function '" 663 << Callee->getName() << "'!\n"; 664 abort(); 665 666 // The setjmp/longjmp intrinsics should only exist in the code if it was 667 // never optimized (ie, right out of the CFE), or if it has been hacked on 668 // by the lowerinvoke pass. In both cases, the right thing to do is to 669 // convert the call to an explicit setjmp or longjmp call. 670 case Intrinsic::setjmp: { 671 static Constant *SetjmpFCache = 0; 672 Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin()+1, CI->op_end(), 673 Type::Int32Ty, SetjmpFCache); 674 if (CI->getType() != Type::VoidTy) 675 CI->replaceAllUsesWith(V); 676 break; 677 } 678 case Intrinsic::sigsetjmp: 679 if (CI->getType() != Type::VoidTy) 680 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 681 break; 682 683 case Intrinsic::longjmp: { 684 static Constant *LongjmpFCache = 0; 685 ReplaceCallWith("longjmp", CI, CI->op_begin()+1, CI->op_end(), 686 Type::VoidTy, LongjmpFCache); 687 break; 688 } 689 690 case Intrinsic::siglongjmp: { 691 // Insert the call to abort 692 static Constant *AbortFCache = 0; 693 ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(), 694 Type::VoidTy, AbortFCache); 695 break; 696 } 697 case Intrinsic::ctpop: 698 CI->replaceAllUsesWith(LowerCTPOP(CI->getOperand(1), CI)); 699 break; 700 701 case Intrinsic::bswap: 702 CI->replaceAllUsesWith(LowerBSWAP(CI->getOperand(1), CI)); 703 break; 704 705 case Intrinsic::ctlz: 706 CI->replaceAllUsesWith(LowerCTLZ(CI->getOperand(1), CI)); 707 break; 708 709 case Intrinsic::cttz: { 710 // cttz(x) -> ctpop(~X & (X-1)) 711 Value *Src = CI->getOperand(1); 712 Value *NotSrc = BinaryOperator::CreateNot(Src, Src->getName()+".not", CI); 713 Value *SrcM1 = ConstantInt::get(Src->getType(), 1); 714 SrcM1 = BinaryOperator::CreateSub(Src, SrcM1, "", CI); 715 Src = LowerCTPOP(BinaryOperator::CreateAnd(NotSrc, SrcM1, "", CI), CI); 716 CI->replaceAllUsesWith(Src); 717 break; 718 } 719 720 case Intrinsic::part_select: 721 CI->replaceAllUsesWith(LowerPartSelect(CI)); 722 break; 723 724 case Intrinsic::part_set: 725 CI->replaceAllUsesWith(LowerPartSet(CI)); 726 break; 727 728 case Intrinsic::stacksave: 729 case Intrinsic::stackrestore: { 730 static bool Warned = false; 731 if (!Warned) 732 cerr << "WARNING: this target does not support the llvm.stack" 733 << (Callee->getIntrinsicID() == Intrinsic::stacksave ? 734 "save" : "restore") << " intrinsic.\n"; 735 Warned = true; 736 if (Callee->getIntrinsicID() == Intrinsic::stacksave) 737 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 738 break; 739 } 740 741 case Intrinsic::returnaddress: 742 case Intrinsic::frameaddress: 743 cerr << "WARNING: this target does not support the llvm." 744 << (Callee->getIntrinsicID() == Intrinsic::returnaddress ? 745 "return" : "frame") << "address intrinsic.\n"; 746 CI->replaceAllUsesWith(ConstantPointerNull::get( 747 cast<PointerType>(CI->getType()))); 748 break; 749 750 case Intrinsic::prefetch: 751 break; // Simply strip out prefetches on unsupported architectures 752 753 case Intrinsic::pcmarker: 754 break; // Simply strip out pcmarker on unsupported architectures 755 case Intrinsic::readcyclecounter: { 756 cerr << "WARNING: this target does not support the llvm.readcyclecoun" 757 << "ter intrinsic. It is being lowered to a constant 0\n"; 758 CI->replaceAllUsesWith(ConstantInt::get(Type::Int64Ty, 0)); 759 break; 760 } 761 762 case Intrinsic::dbg_stoppoint: 763 case Intrinsic::dbg_region_start: 764 case Intrinsic::dbg_region_end: 765 case Intrinsic::dbg_func_start: 766 case Intrinsic::dbg_declare: 767 break; // Simply strip out debugging intrinsics 768 769 case Intrinsic::eh_exception: 770 case Intrinsic::eh_selector_i32: 771 case Intrinsic::eh_selector_i64: 772 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 773 break; 774 775 case Intrinsic::eh_typeid_for_i32: 776 case Intrinsic::eh_typeid_for_i64: 777 // Return something different to eh_selector. 778 CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1)); 779 break; 780 781 case Intrinsic::var_annotation: 782 break; // Strip out annotate intrinsic 783 784 case Intrinsic::memcpy: { 785 static Constant *MemcpyFCache = 0; 786 Value *Size = CI->getOperand(3); 787 const Type *IntPtr = TD.getIntPtrType(); 788 if (Size->getType()->getPrimitiveSizeInBits() < 789 IntPtr->getPrimitiveSizeInBits()) 790 Size = new ZExtInst(Size, IntPtr, "", CI); 791 else if (Size->getType()->getPrimitiveSizeInBits() > 792 IntPtr->getPrimitiveSizeInBits()) 793 Size = new TruncInst(Size, IntPtr, "", CI); 794 Value *Ops[3]; 795 Ops[0] = CI->getOperand(1); 796 Ops[1] = CI->getOperand(2); 797 Ops[2] = Size; 798 ReplaceCallWith("memcpy", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 799 MemcpyFCache); 800 break; 801 } 802 case Intrinsic::memmove: { 803 static Constant *MemmoveFCache = 0; 804 Value *Size = CI->getOperand(3); 805 const Type *IntPtr = TD.getIntPtrType(); 806 if (Size->getType()->getPrimitiveSizeInBits() < 807 IntPtr->getPrimitiveSizeInBits()) 808 Size = new ZExtInst(Size, IntPtr, "", CI); 809 else if (Size->getType()->getPrimitiveSizeInBits() > 810 IntPtr->getPrimitiveSizeInBits()) 811 Size = new TruncInst(Size, IntPtr, "", CI); 812 Value *Ops[3]; 813 Ops[0] = CI->getOperand(1); 814 Ops[1] = CI->getOperand(2); 815 Ops[2] = Size; 816 ReplaceCallWith("memmove", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 817 MemmoveFCache); 818 break; 819 } 820 case Intrinsic::memset: { 821 static Constant *MemsetFCache = 0; 822 Value *Size = CI->getOperand(3); 823 const Type *IntPtr = TD.getIntPtrType(); 824 if (Size->getType()->getPrimitiveSizeInBits() < 825 IntPtr->getPrimitiveSizeInBits()) 826 Size = new ZExtInst(Size, IntPtr, "", CI); 827 else if (Size->getType()->getPrimitiveSizeInBits() > 828 IntPtr->getPrimitiveSizeInBits()) 829 Size = new TruncInst(Size, IntPtr, "", CI); 830 Value *Ops[3]; 831 Ops[0] = CI->getOperand(1); 832 // Extend the amount to i32. 833 Ops[1] = new ZExtInst(CI->getOperand(2), Type::Int32Ty, "", CI); 834 Ops[2] = Size; 835 ReplaceCallWith("memset", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 836 MemsetFCache); 837 break; 838 } 839 case Intrinsic::sqrt: { 840 static Constant *sqrtFCache = 0; 841 static Constant *sqrtDCache = 0; 842 static Constant *sqrtLDCache = 0; 843 ReplaceFPIntrinsicWithCall(CI, sqrtFCache, sqrtDCache, sqrtLDCache, 844 "sqrtf", "sqrt", "sqrtl"); 845 break; 846 } 847 case Intrinsic::log: { 848 static Constant *logFCache = 0; 849 static Constant *logDCache = 0; 850 static Constant *logLDCache = 0; 851 ReplaceFPIntrinsicWithCall(CI, logFCache, logDCache, logLDCache, 852 "logf", "log", "logl"); 853 break; 854 } 855 case Intrinsic::log2: { 856 static Constant *log2FCache = 0; 857 static Constant *log2DCache = 0; 858 static Constant *log2LDCache = 0; 859 ReplaceFPIntrinsicWithCall(CI, log2FCache, log2DCache, log2LDCache, 860 "log2f", "log2", "log2l"); 861 break; 862 } 863 case Intrinsic::log10: { 864 static Constant *log10FCache = 0; 865 static Constant *log10DCache = 0; 866 static Constant *log10LDCache = 0; 867 ReplaceFPIntrinsicWithCall(CI, log10FCache, log10DCache, log10LDCache, 868 "log10f", "log10", "log10l"); 869 break; 870 } 871 case Intrinsic::exp: { 872 static Constant *expFCache = 0; 873 static Constant *expDCache = 0; 874 static Constant *expLDCache = 0; 875 ReplaceFPIntrinsicWithCall(CI, expFCache, expDCache, expLDCache, 876 "expf", "exp", "expl"); 877 break; 878 } 879 case Intrinsic::exp2: { 880 static Constant *exp2FCache = 0; 881 static Constant *exp2DCache = 0; 882 static Constant *exp2LDCache = 0; 883 ReplaceFPIntrinsicWithCall(CI, exp2FCache, exp2DCache, exp2LDCache, 884 "exp2f", "exp2", "exp2l"); 885 break; 886 } 887 case Intrinsic::pow: { 888 static Constant *powFCache = 0; 889 static Constant *powDCache = 0; 890 static Constant *powLDCache = 0; 891 ReplaceFPIntrinsicWithCall(CI, powFCache, powDCache, powLDCache, 892 "powf", "pow", "powl"); 893 break; 894 } 895 case Intrinsic::flt_rounds: 896 // Lower to "round to the nearest" 897 if (CI->getType() != Type::VoidTy) 898 CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1)); 899 break; 900 } 901 902 assert(CI->use_empty() && 903 "Lowering should have eliminated any uses of the intrinsic call!"); 904 CI->eraseFromParent(); 905} 906