IntrinsicLowering.cpp revision 7cbd8a3e92221437048b484d5ef9c0a22d0f8c58
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 37/// ReplaceCallWith - This function is used when we want to lower an intrinsic 38/// call to a call of an external function. This handles hard cases such as 39/// when there was already a prototype for the external function, and if that 40/// prototype doesn't match the arguments we expect to pass in. 41template <class ArgIt> 42static CallInst *ReplaceCallWith(const char *NewFn, CallInst *CI, 43 ArgIt ArgBegin, ArgIt ArgEnd, 44 const Type *RetTy, Constant *&FCache) { 45 if (!FCache) { 46 // If we haven't already looked up this function, check to see if the 47 // program already contains a function with this name. 48 Module *M = CI->getParent()->getParent()->getParent(); 49 // Get or insert the definition now. 50 std::vector<const Type *> ParamTys; 51 for (ArgIt I = ArgBegin; I != ArgEnd; ++I) 52 ParamTys.push_back((*I)->getType()); 53 FCache = M->getOrInsertFunction(NewFn, 54 FunctionType::get(RetTy, ParamTys, false)); 55 } 56 57 SmallVector<Value *, 8> Args(ArgBegin, ArgEnd); 58 CallInst *NewCI = CallInst::Create(FCache, Args.begin(), Args.end(), 59 CI->getName(), CI); 60 if (!CI->use_empty()) 61 CI->replaceAllUsesWith(NewCI); 62 return NewCI; 63} 64 65void IntrinsicLowering::AddPrototypes(Module &M) { 66 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) 67 if (I->isDeclaration() && !I->use_empty()) 68 switch (I->getIntrinsicID()) { 69 default: break; 70 case Intrinsic::setjmp: 71 EnsureFunctionExists(M, "setjmp", I->arg_begin(), I->arg_end(), 72 Type::Int32Ty); 73 break; 74 case Intrinsic::longjmp: 75 EnsureFunctionExists(M, "longjmp", I->arg_begin(), I->arg_end(), 76 Type::VoidTy); 77 break; 78 case Intrinsic::siglongjmp: 79 EnsureFunctionExists(M, "abort", I->arg_end(), I->arg_end(), 80 Type::VoidTy); 81 break; 82 case Intrinsic::memcpy_i32: 83 case Intrinsic::memcpy_i64: 84 M.getOrInsertFunction("memcpy", PointerType::getUnqual(Type::Int8Ty), 85 PointerType::getUnqual(Type::Int8Ty), 86 PointerType::getUnqual(Type::Int8Ty), 87 TD.getIntPtrType(), (Type *)0); 88 break; 89 case Intrinsic::memmove_i32: 90 case Intrinsic::memmove_i64: 91 M.getOrInsertFunction("memmove", PointerType::getUnqual(Type::Int8Ty), 92 PointerType::getUnqual(Type::Int8Ty), 93 PointerType::getUnqual(Type::Int8Ty), 94 TD.getIntPtrType(), (Type *)0); 95 break; 96 case Intrinsic::memset_i32: 97 case Intrinsic::memset_i64: 98 M.getOrInsertFunction("memset", PointerType::getUnqual(Type::Int8Ty), 99 PointerType::getUnqual(Type::Int8Ty), 100 Type::Int32Ty, 101 TD.getIntPtrType(), (Type *)0); 102 break; 103 case Intrinsic::sqrt: 104 switch((int)I->arg_begin()->getType()->getTypeID()) { 105 case Type::FloatTyID: 106 EnsureFunctionExists(M, "sqrtf", I->arg_begin(), I->arg_end(), 107 Type::FloatTy); 108 case Type::DoubleTyID: 109 EnsureFunctionExists(M, "sqrt", I->arg_begin(), I->arg_end(), 110 Type::DoubleTy); 111 case Type::X86_FP80TyID: 112 case Type::FP128TyID: 113 case Type::PPC_FP128TyID: 114 EnsureFunctionExists(M, "sqrtl", I->arg_begin(), I->arg_end(), 115 I->arg_begin()->getType()); 116 } 117 break; 118 case Intrinsic::sin: 119 switch((int)I->arg_begin()->getType()->getTypeID()) { 120 case Type::FloatTyID: 121 EnsureFunctionExists(M, "sinf", I->arg_begin(), I->arg_end(), 122 Type::FloatTy); 123 case Type::DoubleTyID: 124 EnsureFunctionExists(M, "sin", I->arg_begin(), I->arg_end(), 125 Type::DoubleTy); 126 case Type::X86_FP80TyID: 127 case Type::FP128TyID: 128 case Type::PPC_FP128TyID: 129 EnsureFunctionExists(M, "sinl", I->arg_begin(), I->arg_end(), 130 I->arg_begin()->getType()); 131 } 132 break; 133 case Intrinsic::cos: 134 switch((int)I->arg_begin()->getType()->getTypeID()) { 135 case Type::FloatTyID: 136 EnsureFunctionExists(M, "cosf", I->arg_begin(), I->arg_end(), 137 Type::FloatTy); 138 case Type::DoubleTyID: 139 EnsureFunctionExists(M, "cos", I->arg_begin(), I->arg_end(), 140 Type::DoubleTy); 141 case Type::X86_FP80TyID: 142 case Type::FP128TyID: 143 case Type::PPC_FP128TyID: 144 EnsureFunctionExists(M, "cosl", I->arg_begin(), I->arg_end(), 145 I->arg_begin()->getType()); 146 } 147 break; 148 case Intrinsic::pow: 149 switch((int)I->arg_begin()->getType()->getTypeID()) { 150 case Type::FloatTyID: 151 EnsureFunctionExists(M, "powf", I->arg_begin(), I->arg_end(), 152 Type::FloatTy); 153 case Type::DoubleTyID: 154 EnsureFunctionExists(M, "pow", I->arg_begin(), I->arg_end(), 155 Type::DoubleTy); 156 case Type::X86_FP80TyID: 157 case Type::FP128TyID: 158 case Type::PPC_FP128TyID: 159 EnsureFunctionExists(M, "powl", I->arg_begin(), I->arg_end(), 160 I->arg_begin()->getType()); 161 } 162 break; 163 } 164} 165 166/// LowerBSWAP - Emit the code to lower bswap of V before the specified 167/// instruction IP. 168static Value *LowerBSWAP(Value *V, Instruction *IP) { 169 assert(V->getType()->isInteger() && "Can't bswap a non-integer type!"); 170 171 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 172 173 switch(BitSize) { 174 default: assert(0 && "Unhandled type size of value to byteswap!"); 175 case 16: { 176 Value *Tmp1 = BinaryOperator::CreateShl(V, 177 ConstantInt::get(V->getType(),8),"bswap.2",IP); 178 Value *Tmp2 = BinaryOperator::CreateLShr(V, 179 ConstantInt::get(V->getType(),8),"bswap.1",IP); 180 V = BinaryOperator::CreateOr(Tmp1, Tmp2, "bswap.i16", IP); 181 break; 182 } 183 case 32: { 184 Value *Tmp4 = BinaryOperator::CreateShl(V, 185 ConstantInt::get(V->getType(),24),"bswap.4", IP); 186 Value *Tmp3 = BinaryOperator::CreateShl(V, 187 ConstantInt::get(V->getType(),8),"bswap.3",IP); 188 Value *Tmp2 = BinaryOperator::CreateLShr(V, 189 ConstantInt::get(V->getType(),8),"bswap.2",IP); 190 Value *Tmp1 = BinaryOperator::CreateLShr(V, 191 ConstantInt::get(V->getType(),24),"bswap.1", IP); 192 Tmp3 = BinaryOperator::CreateAnd(Tmp3, 193 ConstantInt::get(Type::Int32Ty, 0xFF0000), 194 "bswap.and3", IP); 195 Tmp2 = BinaryOperator::CreateAnd(Tmp2, 196 ConstantInt::get(Type::Int32Ty, 0xFF00), 197 "bswap.and2", IP); 198 Tmp4 = BinaryOperator::CreateOr(Tmp4, Tmp3, "bswap.or1", IP); 199 Tmp2 = BinaryOperator::CreateOr(Tmp2, Tmp1, "bswap.or2", IP); 200 V = BinaryOperator::CreateOr(Tmp4, Tmp2, "bswap.i32", IP); 201 break; 202 } 203 case 64: { 204 Value *Tmp8 = BinaryOperator::CreateShl(V, 205 ConstantInt::get(V->getType(),56),"bswap.8", IP); 206 Value *Tmp7 = BinaryOperator::CreateShl(V, 207 ConstantInt::get(V->getType(),40),"bswap.7", IP); 208 Value *Tmp6 = BinaryOperator::CreateShl(V, 209 ConstantInt::get(V->getType(),24),"bswap.6", IP); 210 Value *Tmp5 = BinaryOperator::CreateShl(V, 211 ConstantInt::get(V->getType(),8),"bswap.5", IP); 212 Value* Tmp4 = BinaryOperator::CreateLShr(V, 213 ConstantInt::get(V->getType(),8),"bswap.4", IP); 214 Value* Tmp3 = BinaryOperator::CreateLShr(V, 215 ConstantInt::get(V->getType(),24),"bswap.3", IP); 216 Value* Tmp2 = BinaryOperator::CreateLShr(V, 217 ConstantInt::get(V->getType(),40),"bswap.2", IP); 218 Value* Tmp1 = BinaryOperator::CreateLShr(V, 219 ConstantInt::get(V->getType(),56),"bswap.1", IP); 220 Tmp7 = BinaryOperator::CreateAnd(Tmp7, 221 ConstantInt::get(Type::Int64Ty, 222 0xFF000000000000ULL), 223 "bswap.and7", IP); 224 Tmp6 = BinaryOperator::CreateAnd(Tmp6, 225 ConstantInt::get(Type::Int64Ty, 0xFF0000000000ULL), 226 "bswap.and6", IP); 227 Tmp5 = BinaryOperator::CreateAnd(Tmp5, 228 ConstantInt::get(Type::Int64Ty, 0xFF00000000ULL), 229 "bswap.and5", IP); 230 Tmp4 = BinaryOperator::CreateAnd(Tmp4, 231 ConstantInt::get(Type::Int64Ty, 0xFF000000ULL), 232 "bswap.and4", IP); 233 Tmp3 = BinaryOperator::CreateAnd(Tmp3, 234 ConstantInt::get(Type::Int64Ty, 0xFF0000ULL), 235 "bswap.and3", IP); 236 Tmp2 = BinaryOperator::CreateAnd(Tmp2, 237 ConstantInt::get(Type::Int64Ty, 0xFF00ULL), 238 "bswap.and2", IP); 239 Tmp8 = BinaryOperator::CreateOr(Tmp8, Tmp7, "bswap.or1", IP); 240 Tmp6 = BinaryOperator::CreateOr(Tmp6, Tmp5, "bswap.or2", IP); 241 Tmp4 = BinaryOperator::CreateOr(Tmp4, Tmp3, "bswap.or3", IP); 242 Tmp2 = BinaryOperator::CreateOr(Tmp2, Tmp1, "bswap.or4", IP); 243 Tmp8 = BinaryOperator::CreateOr(Tmp8, Tmp6, "bswap.or5", IP); 244 Tmp4 = BinaryOperator::CreateOr(Tmp4, Tmp2, "bswap.or6", IP); 245 V = BinaryOperator::CreateOr(Tmp8, Tmp4, "bswap.i64", IP); 246 break; 247 } 248 } 249 return V; 250} 251 252/// LowerCTPOP - Emit the code to lower ctpop of V before the specified 253/// instruction IP. 254static Value *LowerCTPOP(Value *V, Instruction *IP) { 255 assert(V->getType()->isInteger() && "Can't ctpop a non-integer type!"); 256 257 static const uint64_t MaskValues[6] = { 258 0x5555555555555555ULL, 0x3333333333333333ULL, 259 0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL, 260 0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL 261 }; 262 263 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 264 unsigned WordSize = (BitSize + 63) / 64; 265 Value *Count = ConstantInt::get(V->getType(), 0); 266 267 for (unsigned n = 0; n < WordSize; ++n) { 268 Value *PartValue = V; 269 for (unsigned i = 1, ct = 0; i < (BitSize>64 ? 64 : BitSize); 270 i <<= 1, ++ct) { 271 Value *MaskCst = ConstantInt::get(V->getType(), MaskValues[ct]); 272 Value *LHS = BinaryOperator::CreateAnd( 273 PartValue, MaskCst, "cppop.and1", IP); 274 Value *VShift = BinaryOperator::CreateLShr(PartValue, 275 ConstantInt::get(V->getType(), i), "ctpop.sh", IP); 276 Value *RHS = BinaryOperator::CreateAnd(VShift, MaskCst, "cppop.and2", IP); 277 PartValue = BinaryOperator::CreateAdd(LHS, RHS, "ctpop.step", IP); 278 } 279 Count = BinaryOperator::CreateAdd(PartValue, Count, "ctpop.part", IP); 280 if (BitSize > 64) { 281 V = BinaryOperator::CreateLShr(V, ConstantInt::get(V->getType(), 64), 282 "ctpop.part.sh", IP); 283 BitSize -= 64; 284 } 285 } 286 287 return Count; 288} 289 290/// LowerCTLZ - Emit the code to lower ctlz of V before the specified 291/// instruction IP. 292static Value *LowerCTLZ(Value *V, Instruction *IP) { 293 294 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 295 for (unsigned i = 1; i < BitSize; i <<= 1) { 296 Value *ShVal = ConstantInt::get(V->getType(), i); 297 ShVal = BinaryOperator::CreateLShr(V, ShVal, "ctlz.sh", IP); 298 V = BinaryOperator::CreateOr(V, ShVal, "ctlz.step", IP); 299 } 300 301 V = BinaryOperator::CreateNot(V, "", IP); 302 return LowerCTPOP(V, IP); 303} 304 305/// Convert the llvm.part.select.iX.iY intrinsic. This intrinsic takes 306/// three integer arguments. The first argument is the Value from which the 307/// bits will be selected. It may be of any bit width. The second and third 308/// arguments specify a range of bits to select with the second argument 309/// specifying the low bit and the third argument specifying the high bit. Both 310/// must be type i32. The result is the corresponding selected bits from the 311/// Value in the same width as the Value (first argument). If the low bit index 312/// is higher than the high bit index then the inverse selection is done and 313/// the bits are returned in inverse order. 314/// @brief Lowering of llvm.part.select intrinsic. 315static Instruction *LowerPartSelect(CallInst *CI) { 316 // Make sure we're dealing with a part select intrinsic here 317 Function *F = CI->getCalledFunction(); 318 const FunctionType *FT = F->getFunctionType(); 319 if (!F->isDeclaration() || !FT->getReturnType()->isInteger() || 320 FT->getNumParams() != 3 || !FT->getParamType(0)->isInteger() || 321 !FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger()) 322 return CI; 323 324 // Get the intrinsic implementation function by converting all the . to _ 325 // in the intrinsic's function name and then reconstructing the function 326 // declaration. 327 std::string Name(F->getName()); 328 for (unsigned i = 4; i < Name.length(); ++i) 329 if (Name[i] == '.') 330 Name[i] = '_'; 331 Module* M = F->getParent(); 332 F = cast<Function>(M->getOrInsertFunction(Name, FT)); 333 F->setLinkage(GlobalValue::WeakLinkage); 334 335 // If we haven't defined the impl function yet, do so now 336 if (F->isDeclaration()) { 337 338 // Get the arguments to the function 339 Function::arg_iterator args = F->arg_begin(); 340 Value* Val = args++; Val->setName("Val"); 341 Value* Lo = args++; Lo->setName("Lo"); 342 Value* Hi = args++; Hi->setName("High"); 343 344 // We want to select a range of bits here such that [Hi, Lo] is shifted 345 // down to the low bits. However, it is quite possible that Hi is smaller 346 // than Lo in which case the bits have to be reversed. 347 348 // Create the blocks we will need for the two cases (forward, reverse) 349 BasicBlock* CurBB = BasicBlock::Create("entry", F); 350 BasicBlock *RevSize = BasicBlock::Create("revsize", CurBB->getParent()); 351 BasicBlock *FwdSize = BasicBlock::Create("fwdsize", CurBB->getParent()); 352 BasicBlock *Compute = BasicBlock::Create("compute", CurBB->getParent()); 353 BasicBlock *Reverse = BasicBlock::Create("reverse", CurBB->getParent()); 354 BasicBlock *RsltBlk = BasicBlock::Create("result", CurBB->getParent()); 355 356 // Cast Hi and Lo to the size of Val so the widths are all the same 357 if (Hi->getType() != Val->getType()) 358 Hi = CastInst::CreateIntegerCast(Hi, Val->getType(), false, 359 "tmp", CurBB); 360 if (Lo->getType() != Val->getType()) 361 Lo = CastInst::CreateIntegerCast(Lo, Val->getType(), false, 362 "tmp", CurBB); 363 364 // Compute a few things that both cases will need, up front. 365 Constant* Zero = ConstantInt::get(Val->getType(), 0); 366 Constant* One = ConstantInt::get(Val->getType(), 1); 367 Constant* AllOnes = ConstantInt::getAllOnesValue(Val->getType()); 368 369 // Compare the Hi and Lo bit positions. This is used to determine 370 // which case we have (forward or reverse) 371 ICmpInst *Cmp = new ICmpInst(ICmpInst::ICMP_ULT, Hi, Lo, "less",CurBB); 372 BranchInst::Create(RevSize, FwdSize, Cmp, CurBB); 373 374 // First, copmute the number of bits in the forward case. 375 Instruction* FBitSize = 376 BinaryOperator::CreateSub(Hi, Lo,"fbits", FwdSize); 377 BranchInst::Create(Compute, FwdSize); 378 379 // Second, compute the number of bits in the reverse case. 380 Instruction* RBitSize = 381 BinaryOperator::CreateSub(Lo, Hi, "rbits", RevSize); 382 BranchInst::Create(Compute, RevSize); 383 384 // Now, compute the bit range. Start by getting the bitsize and the shift 385 // amount (either Hi or Lo) from PHI nodes. Then we compute a mask for 386 // the number of bits we want in the range. We shift the bits down to the 387 // least significant bits, apply the mask to zero out unwanted high bits, 388 // and we have computed the "forward" result. It may still need to be 389 // reversed. 390 391 // Get the BitSize from one of the two subtractions 392 PHINode *BitSize = PHINode::Create(Val->getType(), "bits", Compute); 393 BitSize->reserveOperandSpace(2); 394 BitSize->addIncoming(FBitSize, FwdSize); 395 BitSize->addIncoming(RBitSize, RevSize); 396 397 // Get the ShiftAmount as the smaller of Hi/Lo 398 PHINode *ShiftAmt = PHINode::Create(Val->getType(), "shiftamt", Compute); 399 ShiftAmt->reserveOperandSpace(2); 400 ShiftAmt->addIncoming(Lo, FwdSize); 401 ShiftAmt->addIncoming(Hi, RevSize); 402 403 // Increment the bit size 404 Instruction *BitSizePlusOne = 405 BinaryOperator::CreateAdd(BitSize, One, "bits", Compute); 406 407 // Create a Mask to zero out the high order bits. 408 Instruction* Mask = 409 BinaryOperator::CreateShl(AllOnes, BitSizePlusOne, "mask", Compute); 410 Mask = BinaryOperator::CreateNot(Mask, "mask", Compute); 411 412 // Shift the bits down and apply the mask 413 Instruction* FRes = 414 BinaryOperator::CreateLShr(Val, ShiftAmt, "fres", Compute); 415 FRes = BinaryOperator::CreateAnd(FRes, Mask, "fres", Compute); 416 BranchInst::Create(Reverse, RsltBlk, Cmp, Compute); 417 418 // In the Reverse block we have the mask already in FRes but we must reverse 419 // it by shifting FRes bits right and putting them in RRes by shifting them 420 // in from left. 421 422 // First set up our loop counters 423 PHINode *Count = PHINode::Create(Val->getType(), "count", Reverse); 424 Count->reserveOperandSpace(2); 425 Count->addIncoming(BitSizePlusOne, Compute); 426 427 // Next, get the value that we are shifting. 428 PHINode *BitsToShift = PHINode::Create(Val->getType(), "val", Reverse); 429 BitsToShift->reserveOperandSpace(2); 430 BitsToShift->addIncoming(FRes, Compute); 431 432 // Finally, get the result of the last computation 433 PHINode *RRes = PHINode::Create(Val->getType(), "rres", Reverse); 434 RRes->reserveOperandSpace(2); 435 RRes->addIncoming(Zero, Compute); 436 437 // Decrement the counter 438 Instruction *Decr = BinaryOperator::CreateSub(Count, One, "decr", Reverse); 439 Count->addIncoming(Decr, Reverse); 440 441 // Compute the Bit that we want to move 442 Instruction *Bit = 443 BinaryOperator::CreateAnd(BitsToShift, One, "bit", Reverse); 444 445 // Compute the new value for next iteration. 446 Instruction *NewVal = 447 BinaryOperator::CreateLShr(BitsToShift, One, "rshift", Reverse); 448 BitsToShift->addIncoming(NewVal, Reverse); 449 450 // Shift the bit into the low bits of the result. 451 Instruction *NewRes = 452 BinaryOperator::CreateShl(RRes, One, "lshift", Reverse); 453 NewRes = BinaryOperator::CreateOr(NewRes, Bit, "addbit", Reverse); 454 RRes->addIncoming(NewRes, Reverse); 455 456 // Terminate loop if we've moved all the bits. 457 ICmpInst *Cond = 458 new ICmpInst(ICmpInst::ICMP_EQ, Decr, Zero, "cond", Reverse); 459 BranchInst::Create(RsltBlk, Reverse, Cond, Reverse); 460 461 // Finally, in the result block, select one of the two results with a PHI 462 // node and return the result; 463 CurBB = RsltBlk; 464 PHINode *BitSelect = PHINode::Create(Val->getType(), "part_select", CurBB); 465 BitSelect->reserveOperandSpace(2); 466 BitSelect->addIncoming(FRes, Compute); 467 BitSelect->addIncoming(NewRes, Reverse); 468 ReturnInst::Create(BitSelect, CurBB); 469 } 470 471 // Return a call to the implementation function 472 Value *Args[] = { 473 CI->getOperand(1), 474 CI->getOperand(2), 475 CI->getOperand(3) 476 }; 477 return CallInst::Create(F, Args, array_endof(Args), CI->getName(), CI); 478} 479 480/// Convert the llvm.part.set.iX.iY.iZ intrinsic. This intrinsic takes 481/// four integer arguments (iAny %Value, iAny %Replacement, i32 %Low, i32 %High) 482/// The first two arguments can be any bit width. The result is the same width 483/// as %Value. The operation replaces bits between %Low and %High with the value 484/// in %Replacement. If %Replacement is not the same width, it is truncated or 485/// zero extended as appropriate to fit the bits being replaced. If %Low is 486/// greater than %High then the inverse set of bits are replaced. 487/// @brief Lowering of llvm.bit.part.set intrinsic. 488static Instruction *LowerPartSet(CallInst *CI) { 489 // Make sure we're dealing with a part select intrinsic here 490 Function *F = CI->getCalledFunction(); 491 const FunctionType *FT = F->getFunctionType(); 492 if (!F->isDeclaration() || !FT->getReturnType()->isInteger() || 493 FT->getNumParams() != 4 || !FT->getParamType(0)->isInteger() || 494 !FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger() || 495 !FT->getParamType(3)->isInteger()) 496 return CI; 497 498 // Get the intrinsic implementation function by converting all the . to _ 499 // in the intrinsic's function name and then reconstructing the function 500 // declaration. 501 std::string Name(F->getName()); 502 for (unsigned i = 4; i < Name.length(); ++i) 503 if (Name[i] == '.') 504 Name[i] = '_'; 505 Module* M = F->getParent(); 506 F = cast<Function>(M->getOrInsertFunction(Name, FT)); 507 F->setLinkage(GlobalValue::WeakLinkage); 508 509 // If we haven't defined the impl function yet, do so now 510 if (F->isDeclaration()) { 511 // Get the arguments for the function. 512 Function::arg_iterator args = F->arg_begin(); 513 Value* Val = args++; Val->setName("Val"); 514 Value* Rep = args++; Rep->setName("Rep"); 515 Value* Lo = args++; Lo->setName("Lo"); 516 Value* Hi = args++; Hi->setName("Hi"); 517 518 // Get some types we need 519 const IntegerType* ValTy = cast<IntegerType>(Val->getType()); 520 const IntegerType* RepTy = cast<IntegerType>(Rep->getType()); 521 uint32_t ValBits = ValTy->getBitWidth(); 522 uint32_t RepBits = RepTy->getBitWidth(); 523 524 // Constant Definitions 525 ConstantInt* RepBitWidth = ConstantInt::get(Type::Int32Ty, RepBits); 526 ConstantInt* RepMask = ConstantInt::getAllOnesValue(RepTy); 527 ConstantInt* ValMask = ConstantInt::getAllOnesValue(ValTy); 528 ConstantInt* One = ConstantInt::get(Type::Int32Ty, 1); 529 ConstantInt* ValOne = ConstantInt::get(ValTy, 1); 530 ConstantInt* Zero = ConstantInt::get(Type::Int32Ty, 0); 531 ConstantInt* ValZero = ConstantInt::get(ValTy, 0); 532 533 // Basic blocks we fill in below. 534 BasicBlock* entry = BasicBlock::Create("entry", F, 0); 535 BasicBlock* large = BasicBlock::Create("large", F, 0); 536 BasicBlock* small = BasicBlock::Create("small", F, 0); 537 BasicBlock* reverse = BasicBlock::Create("reverse", F, 0); 538 BasicBlock* result = BasicBlock::Create("result", F, 0); 539 540 // BASIC BLOCK: entry 541 // First, get the number of bits that we're placing as an i32 542 ICmpInst* is_forward = 543 new ICmpInst(ICmpInst::ICMP_ULT, Lo, Hi, "", entry); 544 SelectInst* Hi_pn = SelectInst::Create(is_forward, Hi, Lo, "", entry); 545 SelectInst* Lo_pn = SelectInst::Create(is_forward, Lo, Hi, "", entry); 546 BinaryOperator* NumBits = BinaryOperator::CreateSub(Hi_pn, Lo_pn, "",entry); 547 NumBits = BinaryOperator::CreateAdd(NumBits, One, "", entry); 548 // Now, convert Lo and Hi to ValTy bit width 549 if (ValBits > 32) { 550 Lo = new ZExtInst(Lo_pn, ValTy, "", entry); 551 } else if (ValBits < 32) { 552 Lo = new TruncInst(Lo_pn, ValTy, "", entry); 553 } 554 // Determine if the replacement bits are larger than the number of bits we 555 // are replacing and deal with it. 556 ICmpInst* is_large = 557 new ICmpInst(ICmpInst::ICMP_ULT, NumBits, RepBitWidth, "", entry); 558 BranchInst::Create(large, small, is_large, entry); 559 560 // BASIC BLOCK: large 561 Instruction* MaskBits = 562 BinaryOperator::CreateSub(RepBitWidth, NumBits, "", large); 563 MaskBits = CastInst::CreateIntegerCast(MaskBits, RepMask->getType(), 564 false, "", large); 565 BinaryOperator* Mask1 = 566 BinaryOperator::CreateLShr(RepMask, MaskBits, "", large); 567 BinaryOperator* Rep2 = BinaryOperator::CreateAnd(Mask1, Rep, "", large); 568 BranchInst::Create(small, large); 569 570 // BASIC BLOCK: small 571 PHINode* Rep3 = PHINode::Create(RepTy, "", small); 572 Rep3->reserveOperandSpace(2); 573 Rep3->addIncoming(Rep2, large); 574 Rep3->addIncoming(Rep, entry); 575 Value* Rep4 = Rep3; 576 if (ValBits > RepBits) 577 Rep4 = new ZExtInst(Rep3, ValTy, "", small); 578 else if (ValBits < RepBits) 579 Rep4 = new TruncInst(Rep3, ValTy, "", small); 580 BranchInst::Create(result, reverse, is_forward, small); 581 582 // BASIC BLOCK: reverse (reverses the bits of the replacement) 583 // Set up our loop counter as a PHI so we can decrement on each iteration. 584 // We will loop for the number of bits in the replacement value. 585 PHINode *Count = PHINode::Create(Type::Int32Ty, "count", reverse); 586 Count->reserveOperandSpace(2); 587 Count->addIncoming(NumBits, small); 588 589 // Get the value that we are shifting bits out of as a PHI because 590 // we'll change this with each iteration. 591 PHINode *BitsToShift = PHINode::Create(Val->getType(), "val", reverse); 592 BitsToShift->reserveOperandSpace(2); 593 BitsToShift->addIncoming(Rep4, small); 594 595 // Get the result of the last computation or zero on first iteration 596 PHINode *RRes = PHINode::Create(Val->getType(), "rres", reverse); 597 RRes->reserveOperandSpace(2); 598 RRes->addIncoming(ValZero, small); 599 600 // Decrement the loop counter by one 601 Instruction *Decr = BinaryOperator::CreateSub(Count, One, "", reverse); 602 Count->addIncoming(Decr, reverse); 603 604 // Get the bit that we want to move into the result 605 Value *Bit = BinaryOperator::CreateAnd(BitsToShift, ValOne, "", reverse); 606 607 // Compute the new value of the bits to shift for the next iteration. 608 Value *NewVal = BinaryOperator::CreateLShr(BitsToShift, ValOne,"", reverse); 609 BitsToShift->addIncoming(NewVal, reverse); 610 611 // Shift the bit we extracted into the low bit of the result. 612 Instruction *NewRes = BinaryOperator::CreateShl(RRes, ValOne, "", reverse); 613 NewRes = BinaryOperator::CreateOr(NewRes, Bit, "", reverse); 614 RRes->addIncoming(NewRes, reverse); 615 616 // Terminate loop if we've moved all the bits. 617 ICmpInst *Cond = new ICmpInst(ICmpInst::ICMP_EQ, Decr, Zero, "", reverse); 618 BranchInst::Create(result, reverse, Cond, reverse); 619 620 // BASIC BLOCK: result 621 PHINode *Rplcmnt = PHINode::Create(Val->getType(), "", result); 622 Rplcmnt->reserveOperandSpace(2); 623 Rplcmnt->addIncoming(NewRes, reverse); 624 Rplcmnt->addIncoming(Rep4, small); 625 Value* t0 = CastInst::CreateIntegerCast(NumBits,ValTy,false,"",result); 626 Value* t1 = BinaryOperator::CreateShl(ValMask, Lo, "", result); 627 Value* t2 = BinaryOperator::CreateNot(t1, "", result); 628 Value* t3 = BinaryOperator::CreateShl(t1, t0, "", result); 629 Value* t4 = BinaryOperator::CreateOr(t2, t3, "", result); 630 Value* t5 = BinaryOperator::CreateAnd(t4, Val, "", result); 631 Value* t6 = BinaryOperator::CreateShl(Rplcmnt, Lo, "", result); 632 Value* Rslt = BinaryOperator::CreateOr(t5, t6, "part_set", result); 633 ReturnInst::Create(Rslt, result); 634 } 635 636 // Return a call to the implementation function 637 Value *Args[] = { 638 CI->getOperand(1), 639 CI->getOperand(2), 640 CI->getOperand(3), 641 CI->getOperand(4) 642 }; 643 return CallInst::Create(F, Args, array_endof(Args), CI->getName(), CI); 644} 645 646 647void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) { 648 Function *Callee = CI->getCalledFunction(); 649 assert(Callee && "Cannot lower an indirect call!"); 650 651 switch (Callee->getIntrinsicID()) { 652 case Intrinsic::not_intrinsic: 653 cerr << "Cannot lower a call to a non-intrinsic function '" 654 << Callee->getName() << "'!\n"; 655 abort(); 656 default: 657 cerr << "Error: Code generator does not support intrinsic function '" 658 << Callee->getName() << "'!\n"; 659 abort(); 660 661 // The setjmp/longjmp intrinsics should only exist in the code if it was 662 // never optimized (ie, right out of the CFE), or if it has been hacked on 663 // by the lowerinvoke pass. In both cases, the right thing to do is to 664 // convert the call to an explicit setjmp or longjmp call. 665 case Intrinsic::setjmp: { 666 static Constant *SetjmpFCache = 0; 667 Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin()+1, CI->op_end(), 668 Type::Int32Ty, SetjmpFCache); 669 if (CI->getType() != Type::VoidTy) 670 CI->replaceAllUsesWith(V); 671 break; 672 } 673 case Intrinsic::sigsetjmp: 674 if (CI->getType() != Type::VoidTy) 675 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 676 break; 677 678 case Intrinsic::longjmp: { 679 static Constant *LongjmpFCache = 0; 680 ReplaceCallWith("longjmp", CI, CI->op_begin()+1, CI->op_end(), 681 Type::VoidTy, LongjmpFCache); 682 break; 683 } 684 685 case Intrinsic::siglongjmp: { 686 // Insert the call to abort 687 static Constant *AbortFCache = 0; 688 ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(), 689 Type::VoidTy, AbortFCache); 690 break; 691 } 692 case Intrinsic::ctpop: 693 CI->replaceAllUsesWith(LowerCTPOP(CI->getOperand(1), CI)); 694 break; 695 696 case Intrinsic::bswap: 697 CI->replaceAllUsesWith(LowerBSWAP(CI->getOperand(1), CI)); 698 break; 699 700 case Intrinsic::ctlz: 701 CI->replaceAllUsesWith(LowerCTLZ(CI->getOperand(1), CI)); 702 break; 703 704 case Intrinsic::cttz: { 705 // cttz(x) -> ctpop(~X & (X-1)) 706 Value *Src = CI->getOperand(1); 707 Value *NotSrc = BinaryOperator::CreateNot(Src, Src->getName()+".not", CI); 708 Value *SrcM1 = ConstantInt::get(Src->getType(), 1); 709 SrcM1 = BinaryOperator::CreateSub(Src, SrcM1, "", CI); 710 Src = LowerCTPOP(BinaryOperator::CreateAnd(NotSrc, SrcM1, "", CI), 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 static bool Warned = false; 726 if (!Warned) 727 cerr << "WARNING: this target does not support the llvm.stack" 728 << (Callee->getIntrinsicID() == Intrinsic::stacksave ? 729 "save" : "restore") << " intrinsic.\n"; 730 Warned = true; 731 if (Callee->getIntrinsicID() == Intrinsic::stacksave) 732 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 733 break; 734 } 735 736 case Intrinsic::returnaddress: 737 case Intrinsic::frameaddress: 738 cerr << "WARNING: this target does not support the llvm." 739 << (Callee->getIntrinsicID() == Intrinsic::returnaddress ? 740 "return" : "frame") << "address intrinsic.\n"; 741 CI->replaceAllUsesWith(ConstantPointerNull::get( 742 cast<PointerType>(CI->getType()))); 743 break; 744 745 case Intrinsic::prefetch: 746 break; // Simply strip out prefetches on unsupported architectures 747 748 case Intrinsic::pcmarker: 749 break; // Simply strip out pcmarker on unsupported architectures 750 case Intrinsic::readcyclecounter: { 751 cerr << "WARNING: this target does not support the llvm.readcyclecoun" 752 << "ter intrinsic. It is being lowered to a constant 0\n"; 753 CI->replaceAllUsesWith(ConstantInt::get(Type::Int64Ty, 0)); 754 break; 755 } 756 757 case Intrinsic::dbg_stoppoint: 758 case Intrinsic::dbg_region_start: 759 case Intrinsic::dbg_region_end: 760 case Intrinsic::dbg_func_start: 761 case Intrinsic::dbg_declare: 762 break; // Simply strip out debugging intrinsics 763 764 case Intrinsic::eh_exception: 765 case Intrinsic::eh_selector_i32: 766 case Intrinsic::eh_selector_i64: 767 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 768 break; 769 770 case Intrinsic::eh_typeid_for_i32: 771 case Intrinsic::eh_typeid_for_i64: 772 // Return something different to eh_selector. 773 CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1)); 774 break; 775 776 case Intrinsic::var_annotation: 777 break; // Strip out annotate intrinsic 778 779 case Intrinsic::memcpy_i32: 780 case Intrinsic::memcpy_i64: { 781 static Constant *MemcpyFCache = 0; 782 Value *Size = CI->getOperand(3); 783 const Type *IntPtr = TD.getIntPtrType(); 784 if (Size->getType()->getPrimitiveSizeInBits() < 785 IntPtr->getPrimitiveSizeInBits()) 786 Size = new ZExtInst(Size, IntPtr, "", CI); 787 else if (Size->getType()->getPrimitiveSizeInBits() > 788 IntPtr->getPrimitiveSizeInBits()) 789 Size = new TruncInst(Size, IntPtr, "", CI); 790 Value *Ops[3]; 791 Ops[0] = CI->getOperand(1); 792 Ops[1] = CI->getOperand(2); 793 Ops[2] = Size; 794 ReplaceCallWith("memcpy", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 795 MemcpyFCache); 796 break; 797 } 798 case Intrinsic::memmove_i32: 799 case Intrinsic::memmove_i64: { 800 static Constant *MemmoveFCache = 0; 801 Value *Size = CI->getOperand(3); 802 const Type *IntPtr = TD.getIntPtrType(); 803 if (Size->getType()->getPrimitiveSizeInBits() < 804 IntPtr->getPrimitiveSizeInBits()) 805 Size = new ZExtInst(Size, IntPtr, "", CI); 806 else if (Size->getType()->getPrimitiveSizeInBits() > 807 IntPtr->getPrimitiveSizeInBits()) 808 Size = new TruncInst(Size, IntPtr, "", CI); 809 Value *Ops[3]; 810 Ops[0] = CI->getOperand(1); 811 Ops[1] = CI->getOperand(2); 812 Ops[2] = Size; 813 ReplaceCallWith("memmove", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 814 MemmoveFCache); 815 break; 816 } 817 case Intrinsic::memset_i32: 818 case Intrinsic::memset_i64: { 819 static Constant *MemsetFCache = 0; 820 Value *Size = CI->getOperand(3); 821 const Type *IntPtr = TD.getIntPtrType(); 822 if (Size->getType()->getPrimitiveSizeInBits() < 823 IntPtr->getPrimitiveSizeInBits()) 824 Size = new ZExtInst(Size, IntPtr, "", CI); 825 else if (Size->getType()->getPrimitiveSizeInBits() > 826 IntPtr->getPrimitiveSizeInBits()) 827 Size = new TruncInst(Size, IntPtr, "", CI); 828 Value *Ops[3]; 829 Ops[0] = CI->getOperand(1); 830 // Extend the amount to i32. 831 Ops[1] = new ZExtInst(CI->getOperand(2), Type::Int32Ty, "", CI); 832 Ops[2] = Size; 833 ReplaceCallWith("memset", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 834 MemsetFCache); 835 break; 836 } 837 case Intrinsic::sqrt: { 838 static Constant *sqrtfFCache = 0; 839 static Constant *sqrtFCache = 0; 840 static Constant *sqrtLDCache = 0; 841 switch (CI->getOperand(1)->getType()->getTypeID()) { 842 default: assert(0 && "Invalid type in sqrt"); abort(); 843 case Type::FloatTyID: 844 ReplaceCallWith("sqrtf", CI, CI->op_begin()+1, CI->op_end(), 845 Type::FloatTy, sqrtfFCache); 846 break; 847 case Type::DoubleTyID: 848 ReplaceCallWith("sqrt", CI, CI->op_begin()+1, CI->op_end(), 849 Type::DoubleTy, sqrtFCache); 850 break; 851 case Type::X86_FP80TyID: 852 case Type::FP128TyID: 853 case Type::PPC_FP128TyID: 854 ReplaceCallWith("sqrtl", CI, CI->op_begin()+1, CI->op_end(), 855 CI->getOperand(1)->getType(), sqrtLDCache); 856 break; 857 } 858 break; 859 } 860 case Intrinsic::flt_rounds: 861 // Lower to "round to the nearest" 862 if (CI->getType() != Type::VoidTy) 863 CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1)); 864 break; 865 } 866 867 assert(CI->use_empty() && 868 "Lowering should have eliminated any uses of the intrinsic call!"); 869 CI->eraseFromParent(); 870} 871