IntrinsicLowering.cpp revision 1636de94069d492185da2dd36859d4a1962a2eed
1//===-- IntrinsicLowering.cpp - Intrinsic Lowering default implementation -===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file was developed by the LLVM research group and is distributed under 6// the University of Illinois Open Source License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements the 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 = new CallInst(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::get(Type::Int8Ty), 85 PointerType::get(Type::Int8Ty), 86 PointerType::get(Type::Int8Ty), 87 TD.getIntPtrType(), (Type *)0); 88 break; 89 case Intrinsic::memmove_i32: 90 case Intrinsic::memmove_i64: 91 M.getOrInsertFunction("memmove", PointerType::get(Type::Int8Ty), 92 PointerType::get(Type::Int8Ty), 93 PointerType::get(Type::Int8Ty), 94 TD.getIntPtrType(), (Type *)0); 95 break; 96 case Intrinsic::memset_i32: 97 case Intrinsic::memset_i64: 98 M.getOrInsertFunction("memset", PointerType::get(Type::Int8Ty), 99 PointerType::get(Type::Int8Ty), Type::Int32Ty, 100 TD.getIntPtrType(), (Type *)0); 101 break; 102 case Intrinsic::sqrt_f32: 103 case Intrinsic::sqrt_f64: 104 if(I->arg_begin()->getType() == Type::FloatTy) 105 EnsureFunctionExists(M, "sqrtf", I->arg_begin(), I->arg_end(), 106 Type::FloatTy); 107 else 108 EnsureFunctionExists(M, "sqrt", I->arg_begin(), I->arg_end(), 109 Type::DoubleTy); 110 break; 111 } 112} 113 114/// LowerBSWAP - Emit the code to lower bswap of V before the specified 115/// instruction IP. 116static Value *LowerBSWAP(Value *V, Instruction *IP) { 117 assert(V->getType()->isInteger() && "Can't bswap a non-integer type!"); 118 119 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 120 121 switch(BitSize) { 122 default: assert(0 && "Unhandled type size of value to byteswap!"); 123 case 16: { 124 Value *Tmp1 = BinaryOperator::createShl(V, 125 ConstantInt::get(V->getType(),8),"bswap.2",IP); 126 Value *Tmp2 = BinaryOperator::createLShr(V, 127 ConstantInt::get(V->getType(),8),"bswap.1",IP); 128 V = BinaryOperator::createOr(Tmp1, Tmp2, "bswap.i16", IP); 129 break; 130 } 131 case 32: { 132 Value *Tmp4 = BinaryOperator::createShl(V, 133 ConstantInt::get(V->getType(),24),"bswap.4", IP); 134 Value *Tmp3 = BinaryOperator::createShl(V, 135 ConstantInt::get(V->getType(),8),"bswap.3",IP); 136 Value *Tmp2 = BinaryOperator::createLShr(V, 137 ConstantInt::get(V->getType(),8),"bswap.2",IP); 138 Value *Tmp1 = BinaryOperator::createLShr(V, 139 ConstantInt::get(V->getType(),24),"bswap.1", IP); 140 Tmp3 = BinaryOperator::createAnd(Tmp3, 141 ConstantInt::get(Type::Int32Ty, 0xFF0000), 142 "bswap.and3", IP); 143 Tmp2 = BinaryOperator::createAnd(Tmp2, 144 ConstantInt::get(Type::Int32Ty, 0xFF00), 145 "bswap.and2", IP); 146 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp3, "bswap.or1", IP); 147 Tmp2 = BinaryOperator::createOr(Tmp2, Tmp1, "bswap.or2", IP); 148 V = BinaryOperator::createOr(Tmp4, Tmp2, "bswap.i32", IP); 149 break; 150 } 151 case 64: { 152 Value *Tmp8 = BinaryOperator::createShl(V, 153 ConstantInt::get(V->getType(),56),"bswap.8", IP); 154 Value *Tmp7 = BinaryOperator::createShl(V, 155 ConstantInt::get(V->getType(),40),"bswap.7", IP); 156 Value *Tmp6 = BinaryOperator::createShl(V, 157 ConstantInt::get(V->getType(),24),"bswap.6", IP); 158 Value *Tmp5 = BinaryOperator::createShl(V, 159 ConstantInt::get(V->getType(),8),"bswap.5", IP); 160 Value* Tmp4 = BinaryOperator::createLShr(V, 161 ConstantInt::get(V->getType(),8),"bswap.4", IP); 162 Value* Tmp3 = BinaryOperator::createLShr(V, 163 ConstantInt::get(V->getType(),24),"bswap.3", IP); 164 Value* Tmp2 = BinaryOperator::createLShr(V, 165 ConstantInt::get(V->getType(),40),"bswap.2", IP); 166 Value* Tmp1 = BinaryOperator::createLShr(V, 167 ConstantInt::get(V->getType(),56),"bswap.1", IP); 168 Tmp7 = BinaryOperator::createAnd(Tmp7, 169 ConstantInt::get(Type::Int64Ty, 170 0xFF000000000000ULL), 171 "bswap.and7", IP); 172 Tmp6 = BinaryOperator::createAnd(Tmp6, 173 ConstantInt::get(Type::Int64Ty, 0xFF0000000000ULL), 174 "bswap.and6", IP); 175 Tmp5 = BinaryOperator::createAnd(Tmp5, 176 ConstantInt::get(Type::Int64Ty, 0xFF00000000ULL), 177 "bswap.and5", IP); 178 Tmp4 = BinaryOperator::createAnd(Tmp4, 179 ConstantInt::get(Type::Int64Ty, 0xFF000000ULL), 180 "bswap.and4", IP); 181 Tmp3 = BinaryOperator::createAnd(Tmp3, 182 ConstantInt::get(Type::Int64Ty, 0xFF0000ULL), 183 "bswap.and3", IP); 184 Tmp2 = BinaryOperator::createAnd(Tmp2, 185 ConstantInt::get(Type::Int64Ty, 0xFF00ULL), 186 "bswap.and2", IP); 187 Tmp8 = BinaryOperator::createOr(Tmp8, Tmp7, "bswap.or1", IP); 188 Tmp6 = BinaryOperator::createOr(Tmp6, Tmp5, "bswap.or2", IP); 189 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp3, "bswap.or3", IP); 190 Tmp2 = BinaryOperator::createOr(Tmp2, Tmp1, "bswap.or4", IP); 191 Tmp8 = BinaryOperator::createOr(Tmp8, Tmp6, "bswap.or5", IP); 192 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp2, "bswap.or6", IP); 193 V = BinaryOperator::createOr(Tmp8, Tmp4, "bswap.i64", IP); 194 break; 195 } 196 } 197 return V; 198} 199 200/// LowerCTPOP - Emit the code to lower ctpop of V before the specified 201/// instruction IP. 202static Value *LowerCTPOP(Value *V, Instruction *IP) { 203 assert(V->getType()->isInteger() && "Can't ctpop a non-integer type!"); 204 205 static const uint64_t MaskValues[6] = { 206 0x5555555555555555ULL, 0x3333333333333333ULL, 207 0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL, 208 0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL 209 }; 210 211 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 212 unsigned WordSize = (BitSize + 63) / 64; 213 Value *Count = ConstantInt::get(V->getType(), 0); 214 215 for (unsigned n = 0; n < WordSize; ++n) { 216 Value *PartValue = V; 217 for (unsigned i = 1, ct = 0; i < (BitSize>64 ? 64 : BitSize); 218 i <<= 1, ++ct) { 219 Value *MaskCst = ConstantInt::get(V->getType(), MaskValues[ct]); 220 Value *LHS = BinaryOperator::createAnd( 221 PartValue, MaskCst, "cppop.and1", IP); 222 Value *VShift = BinaryOperator::createLShr(PartValue, 223 ConstantInt::get(V->getType(), i), "ctpop.sh", IP); 224 Value *RHS = BinaryOperator::createAnd(VShift, MaskCst, "cppop.and2", IP); 225 PartValue = BinaryOperator::createAdd(LHS, RHS, "ctpop.step", IP); 226 } 227 Count = BinaryOperator::createAdd(PartValue, Count, "ctpop.part", IP); 228 if (BitSize > 64) { 229 V = BinaryOperator::createLShr(V, ConstantInt::get(V->getType(), 64), 230 "ctpop.part.sh", IP); 231 BitSize -= 64; 232 } 233 } 234 235 return Count; 236} 237 238/// LowerCTLZ - Emit the code to lower ctlz of V before the specified 239/// instruction IP. 240static Value *LowerCTLZ(Value *V, Instruction *IP) { 241 242 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 243 for (unsigned i = 1; i < BitSize; i <<= 1) { 244 Value *ShVal = ConstantInt::get(V->getType(), i); 245 ShVal = BinaryOperator::createLShr(V, ShVal, "ctlz.sh", IP); 246 V = BinaryOperator::createOr(V, ShVal, "ctlz.step", IP); 247 } 248 249 V = BinaryOperator::createNot(V, "", IP); 250 return LowerCTPOP(V, IP); 251} 252 253/// Convert the llvm.part.select.iX.iY intrinsic. This intrinsic takes 254/// three integer arguments. The first argument is the Value from which the 255/// bits will be selected. It may be of any bit width. The second and third 256/// arguments specify a range of bits to select with the second argument 257/// specifying the low bit and the third argument specifying the high bit. Both 258/// must be type i32. The result is the corresponding selected bits from the 259/// Value in the same width as the Value (first argument). If the low bit index 260/// is higher than the high bit index then the inverse selection is done and 261/// the bits are returned in inverse order. 262/// @brief Lowering of llvm.part.select intrinsic. 263static Instruction *LowerPartSelect(CallInst *CI) { 264 // Make sure we're dealing with a part select intrinsic here 265 Function *F = CI->getCalledFunction(); 266 const FunctionType *FT = F->getFunctionType(); 267 if (!F->isDeclaration() || !FT->getReturnType()->isInteger() || 268 FT->getNumParams() != 3 || !FT->getParamType(0)->isInteger() || 269 !FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger()) 270 return CI; 271 272 // Get the intrinsic implementation function by converting all the . to _ 273 // in the intrinsic's function name and then reconstructing the function 274 // declaration. 275 std::string Name(F->getName()); 276 for (unsigned i = 4; i < Name.length(); ++i) 277 if (Name[i] == '.') 278 Name[i] = '_'; 279 Module* M = F->getParent(); 280 F = cast<Function>(M->getOrInsertFunction(Name, FT)); 281 F->setLinkage(GlobalValue::WeakLinkage); 282 283 // If we haven't defined the impl function yet, do so now 284 if (F->isDeclaration()) { 285 286 // Get the arguments to the function 287 Function::arg_iterator args = F->arg_begin(); 288 Value* Val = args++; Val->setName("Val"); 289 Value* Lo = args++; Lo->setName("Lo"); 290 Value* Hi = args++; Hi->setName("High"); 291 292 // We want to select a range of bits here such that [Hi, Lo] is shifted 293 // down to the low bits. However, it is quite possible that Hi is smaller 294 // than Lo in which case the bits have to be reversed. 295 296 // Create the blocks we will need for the two cases (forward, reverse) 297 BasicBlock* CurBB = new BasicBlock("entry", F); 298 BasicBlock *RevSize = new BasicBlock("revsize", CurBB->getParent()); 299 BasicBlock *FwdSize = new BasicBlock("fwdsize", CurBB->getParent()); 300 BasicBlock *Compute = new BasicBlock("compute", CurBB->getParent()); 301 BasicBlock *Reverse = new BasicBlock("reverse", CurBB->getParent()); 302 BasicBlock *RsltBlk = new BasicBlock("result", CurBB->getParent()); 303 304 // Cast Hi and Lo to the size of Val so the widths are all the same 305 if (Hi->getType() != Val->getType()) 306 Hi = CastInst::createIntegerCast(Hi, Val->getType(), false, 307 "tmp", CurBB); 308 if (Lo->getType() != Val->getType()) 309 Lo = CastInst::createIntegerCast(Lo, Val->getType(), false, 310 "tmp", CurBB); 311 312 // Compute a few things that both cases will need, up front. 313 Constant* Zero = ConstantInt::get(Val->getType(), 0); 314 Constant* One = ConstantInt::get(Val->getType(), 1); 315 Constant* AllOnes = ConstantInt::getAllOnesValue(Val->getType()); 316 317 // Compare the Hi and Lo bit positions. This is used to determine 318 // which case we have (forward or reverse) 319 ICmpInst *Cmp = new ICmpInst(ICmpInst::ICMP_ULT, Hi, Lo, "less",CurBB); 320 new BranchInst(RevSize, FwdSize, Cmp, CurBB); 321 322 // First, copmute the number of bits in the forward case. 323 Instruction* FBitSize = 324 BinaryOperator::createSub(Hi, Lo,"fbits", FwdSize); 325 new BranchInst(Compute, FwdSize); 326 327 // Second, compute the number of bits in the reverse case. 328 Instruction* RBitSize = 329 BinaryOperator::createSub(Lo, Hi, "rbits", RevSize); 330 new BranchInst(Compute, RevSize); 331 332 // Now, compute the bit range. Start by getting the bitsize and the shift 333 // amount (either Hi or Lo) from PHI nodes. Then we compute a mask for 334 // the number of bits we want in the range. We shift the bits down to the 335 // least significant bits, apply the mask to zero out unwanted high bits, 336 // and we have computed the "forward" result. It may still need to be 337 // reversed. 338 339 // Get the BitSize from one of the two subtractions 340 PHINode *BitSize = new PHINode(Val->getType(), "bits", Compute); 341 BitSize->reserveOperandSpace(2); 342 BitSize->addIncoming(FBitSize, FwdSize); 343 BitSize->addIncoming(RBitSize, RevSize); 344 345 // Get the ShiftAmount as the smaller of Hi/Lo 346 PHINode *ShiftAmt = new PHINode(Val->getType(), "shiftamt", Compute); 347 ShiftAmt->reserveOperandSpace(2); 348 ShiftAmt->addIncoming(Lo, FwdSize); 349 ShiftAmt->addIncoming(Hi, RevSize); 350 351 // Increment the bit size 352 Instruction *BitSizePlusOne = 353 BinaryOperator::createAdd(BitSize, One, "bits", Compute); 354 355 // Create a Mask to zero out the high order bits. 356 Instruction* Mask = 357 BinaryOperator::createShl(AllOnes, BitSizePlusOne, "mask", Compute); 358 Mask = BinaryOperator::createNot(Mask, "mask", Compute); 359 360 // Shift the bits down and apply the mask 361 Instruction* FRes = 362 BinaryOperator::createLShr(Val, ShiftAmt, "fres", Compute); 363 FRes = BinaryOperator::createAnd(FRes, Mask, "fres", Compute); 364 new BranchInst(Reverse, RsltBlk, Cmp, Compute); 365 366 // In the Reverse block we have the mask already in FRes but we must reverse 367 // it by shifting FRes bits right and putting them in RRes by shifting them 368 // in from left. 369 370 // First set up our loop counters 371 PHINode *Count = new PHINode(Val->getType(), "count", Reverse); 372 Count->reserveOperandSpace(2); 373 Count->addIncoming(BitSizePlusOne, Compute); 374 375 // Next, get the value that we are shifting. 376 PHINode *BitsToShift = new PHINode(Val->getType(), "val", Reverse); 377 BitsToShift->reserveOperandSpace(2); 378 BitsToShift->addIncoming(FRes, Compute); 379 380 // Finally, get the result of the last computation 381 PHINode *RRes = new PHINode(Val->getType(), "rres", Reverse); 382 RRes->reserveOperandSpace(2); 383 RRes->addIncoming(Zero, Compute); 384 385 // Decrement the counter 386 Instruction *Decr = BinaryOperator::createSub(Count, One, "decr", Reverse); 387 Count->addIncoming(Decr, Reverse); 388 389 // Compute the Bit that we want to move 390 Instruction *Bit = 391 BinaryOperator::createAnd(BitsToShift, One, "bit", Reverse); 392 393 // Compute the new value for next iteration. 394 Instruction *NewVal = 395 BinaryOperator::createLShr(BitsToShift, One, "rshift", Reverse); 396 BitsToShift->addIncoming(NewVal, Reverse); 397 398 // Shift the bit into the low bits of the result. 399 Instruction *NewRes = 400 BinaryOperator::createShl(RRes, One, "lshift", Reverse); 401 NewRes = BinaryOperator::createOr(NewRes, Bit, "addbit", Reverse); 402 RRes->addIncoming(NewRes, Reverse); 403 404 // Terminate loop if we've moved all the bits. 405 ICmpInst *Cond = 406 new ICmpInst(ICmpInst::ICMP_EQ, Decr, Zero, "cond", Reverse); 407 new BranchInst(RsltBlk, Reverse, Cond, Reverse); 408 409 // Finally, in the result block, select one of the two results with a PHI 410 // node and return the result; 411 CurBB = RsltBlk; 412 PHINode *BitSelect = new PHINode(Val->getType(), "part_select", CurBB); 413 BitSelect->reserveOperandSpace(2); 414 BitSelect->addIncoming(FRes, Compute); 415 BitSelect->addIncoming(NewRes, Reverse); 416 new ReturnInst(BitSelect, CurBB); 417 } 418 419 // Return a call to the implementation function 420 Value *Args[] = { 421 CI->getOperand(1), 422 CI->getOperand(2), 423 CI->getOperand(3) 424 }; 425 return new CallInst(F, Args, array_endof(Args), CI->getName(), CI); 426} 427 428/// Convert the llvm.part.set.iX.iY.iZ intrinsic. This intrinsic takes 429/// four integer arguments (iAny %Value, iAny %Replacement, i32 %Low, i32 %High) 430/// The first two arguments can be any bit width. The result is the same width 431/// as %Value. The operation replaces bits between %Low and %High with the value 432/// in %Replacement. If %Replacement is not the same width, it is truncated or 433/// zero extended as appropriate to fit the bits being replaced. If %Low is 434/// greater than %High then the inverse set of bits are replaced. 435/// @brief Lowering of llvm.bit.part.set intrinsic. 436static Instruction *LowerPartSet(CallInst *CI) { 437 // Make sure we're dealing with a part select intrinsic here 438 Function *F = CI->getCalledFunction(); 439 const FunctionType *FT = F->getFunctionType(); 440 if (!F->isDeclaration() || !FT->getReturnType()->isInteger() || 441 FT->getNumParams() != 4 || !FT->getParamType(0)->isInteger() || 442 !FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger() || 443 !FT->getParamType(3)->isInteger()) 444 return CI; 445 446 // Get the intrinsic implementation function by converting all the . to _ 447 // in the intrinsic's function name and then reconstructing the function 448 // declaration. 449 std::string Name(F->getName()); 450 for (unsigned i = 4; i < Name.length(); ++i) 451 if (Name[i] == '.') 452 Name[i] = '_'; 453 Module* M = F->getParent(); 454 F = cast<Function>(M->getOrInsertFunction(Name, FT)); 455 F->setLinkage(GlobalValue::WeakLinkage); 456 457 // If we haven't defined the impl function yet, do so now 458 if (F->isDeclaration()) { 459 // Get the arguments for the function. 460 Function::arg_iterator args = F->arg_begin(); 461 Value* Val = args++; Val->setName("Val"); 462 Value* Rep = args++; Rep->setName("Rep"); 463 Value* Lo = args++; Lo->setName("Lo"); 464 Value* Hi = args++; Hi->setName("Hi"); 465 466 // Get some types we need 467 const IntegerType* ValTy = cast<IntegerType>(Val->getType()); 468 const IntegerType* RepTy = cast<IntegerType>(Rep->getType()); 469 uint32_t ValBits = ValTy->getBitWidth(); 470 uint32_t RepBits = RepTy->getBitWidth(); 471 472 // Constant Definitions 473 ConstantInt* RepBitWidth = ConstantInt::get(Type::Int32Ty, RepBits); 474 ConstantInt* RepMask = ConstantInt::getAllOnesValue(RepTy); 475 ConstantInt* ValMask = ConstantInt::getAllOnesValue(ValTy); 476 ConstantInt* One = ConstantInt::get(Type::Int32Ty, 1); 477 ConstantInt* ValOne = ConstantInt::get(ValTy, 1); 478 ConstantInt* Zero = ConstantInt::get(Type::Int32Ty, 0); 479 ConstantInt* ValZero = ConstantInt::get(ValTy, 0); 480 481 // Basic blocks we fill in below. 482 BasicBlock* entry = new BasicBlock("entry", F, 0); 483 BasicBlock* large = new BasicBlock("large", F, 0); 484 BasicBlock* small = new BasicBlock("small", F, 0); 485 BasicBlock* reverse = new BasicBlock("reverse", F, 0); 486 BasicBlock* result = new BasicBlock("result", F, 0); 487 488 // BASIC BLOCK: entry 489 // First, get the number of bits that we're placing as an i32 490 ICmpInst* is_forward = 491 new ICmpInst(ICmpInst::ICMP_ULT, Lo, Hi, "", entry); 492 SelectInst* Hi_pn = new SelectInst(is_forward, Hi, Lo, "", entry); 493 SelectInst* Lo_pn = new SelectInst(is_forward, Lo, Hi, "", entry); 494 BinaryOperator* NumBits = BinaryOperator::createSub(Hi_pn, Lo_pn, "",entry); 495 NumBits = BinaryOperator::createAdd(NumBits, One, "", entry); 496 // Now, convert Lo and Hi to ValTy bit width 497 if (ValBits > 32) { 498 Lo = new ZExtInst(Lo_pn, ValTy, "", entry); 499 } else if (ValBits < 32) { 500 Lo = new TruncInst(Lo_pn, ValTy, "", entry); 501 } 502 // Determine if the replacement bits are larger than the number of bits we 503 // are replacing and deal with it. 504 ICmpInst* is_large = 505 new ICmpInst(ICmpInst::ICMP_ULT, NumBits, RepBitWidth, "", entry); 506 new BranchInst(large, small, is_large, entry); 507 508 // BASIC BLOCK: large 509 Instruction* MaskBits = 510 BinaryOperator::createSub(RepBitWidth, NumBits, "", large); 511 MaskBits = CastInst::createIntegerCast(MaskBits, RepMask->getType(), 512 false, "", large); 513 BinaryOperator* Mask1 = 514 BinaryOperator::createLShr(RepMask, MaskBits, "", large); 515 BinaryOperator* Rep2 = BinaryOperator::createAnd(Mask1, Rep, "", large); 516 new BranchInst(small, large); 517 518 // BASIC BLOCK: small 519 PHINode* Rep3 = new PHINode(RepTy, "", small); 520 Rep3->reserveOperandSpace(2); 521 Rep3->addIncoming(Rep2, large); 522 Rep3->addIncoming(Rep, entry); 523 Value* Rep4 = Rep3; 524 if (ValBits > RepBits) 525 Rep4 = new ZExtInst(Rep3, ValTy, "", small); 526 else if (ValBits < RepBits) 527 Rep4 = new TruncInst(Rep3, ValTy, "", small); 528 new BranchInst(result, reverse, is_forward, small); 529 530 // BASIC BLOCK: reverse (reverses the bits of the replacement) 531 // Set up our loop counter as a PHI so we can decrement on each iteration. 532 // We will loop for the number of bits in the replacement value. 533 PHINode *Count = new PHINode(Type::Int32Ty, "count", reverse); 534 Count->reserveOperandSpace(2); 535 Count->addIncoming(NumBits, small); 536 537 // Get the value that we are shifting bits out of as a PHI because 538 // we'll change this with each iteration. 539 PHINode *BitsToShift = new PHINode(Val->getType(), "val", reverse); 540 BitsToShift->reserveOperandSpace(2); 541 BitsToShift->addIncoming(Rep4, small); 542 543 // Get the result of the last computation or zero on first iteration 544 PHINode *RRes = new PHINode(Val->getType(), "rres", reverse); 545 RRes->reserveOperandSpace(2); 546 RRes->addIncoming(ValZero, small); 547 548 // Decrement the loop counter by one 549 Instruction *Decr = BinaryOperator::createSub(Count, One, "", reverse); 550 Count->addIncoming(Decr, reverse); 551 552 // Get the bit that we want to move into the result 553 Value *Bit = BinaryOperator::createAnd(BitsToShift, ValOne, "", reverse); 554 555 // Compute the new value of the bits to shift for the next iteration. 556 Value *NewVal = BinaryOperator::createLShr(BitsToShift, ValOne,"", reverse); 557 BitsToShift->addIncoming(NewVal, reverse); 558 559 // Shift the bit we extracted into the low bit of the result. 560 Instruction *NewRes = BinaryOperator::createShl(RRes, ValOne, "", reverse); 561 NewRes = BinaryOperator::createOr(NewRes, Bit, "", reverse); 562 RRes->addIncoming(NewRes, reverse); 563 564 // Terminate loop if we've moved all the bits. 565 ICmpInst *Cond = new ICmpInst(ICmpInst::ICMP_EQ, Decr, Zero, "", reverse); 566 new BranchInst(result, reverse, Cond, reverse); 567 568 // BASIC BLOCK: result 569 PHINode *Rplcmnt = new PHINode(Val->getType(), "", result); 570 Rplcmnt->reserveOperandSpace(2); 571 Rplcmnt->addIncoming(NewRes, reverse); 572 Rplcmnt->addIncoming(Rep4, small); 573 Value* t0 = CastInst::createIntegerCast(NumBits,ValTy,false,"",result); 574 Value* t1 = BinaryOperator::createShl(ValMask, Lo, "", result); 575 Value* t2 = BinaryOperator::createNot(t1, "", result); 576 Value* t3 = BinaryOperator::createShl(t1, t0, "", result); 577 Value* t4 = BinaryOperator::createOr(t2, t3, "", result); 578 Value* t5 = BinaryOperator::createAnd(t4, Val, "", result); 579 Value* t6 = BinaryOperator::createShl(Rplcmnt, Lo, "", result); 580 Value* Rslt = BinaryOperator::createOr(t5, t6, "part_set", result); 581 new ReturnInst(Rslt, result); 582 } 583 584 // Return a call to the implementation function 585 Value *Args[] = { 586 CI->getOperand(1), 587 CI->getOperand(2), 588 CI->getOperand(3), 589 CI->getOperand(4) 590 }; 591 return new CallInst(F, Args, array_endof(Args), CI->getName(), CI); 592} 593 594 595void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) { 596 Function *Callee = CI->getCalledFunction(); 597 assert(Callee && "Cannot lower an indirect call!"); 598 599 switch (Callee->getIntrinsicID()) { 600 case Intrinsic::not_intrinsic: 601 cerr << "Cannot lower a call to a non-intrinsic function '" 602 << Callee->getName() << "'!\n"; 603 abort(); 604 default: 605 cerr << "Error: Code generator does not support intrinsic function '" 606 << Callee->getName() << "'!\n"; 607 abort(); 608 609 // The setjmp/longjmp intrinsics should only exist in the code if it was 610 // never optimized (ie, right out of the CFE), or if it has been hacked on 611 // by the lowerinvoke pass. In both cases, the right thing to do is to 612 // convert the call to an explicit setjmp or longjmp call. 613 case Intrinsic::setjmp: { 614 static Constant *SetjmpFCache = 0; 615 Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin()+1, CI->op_end(), 616 Type::Int32Ty, SetjmpFCache); 617 if (CI->getType() != Type::VoidTy) 618 CI->replaceAllUsesWith(V); 619 break; 620 } 621 case Intrinsic::sigsetjmp: 622 if (CI->getType() != Type::VoidTy) 623 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 624 break; 625 626 case Intrinsic::longjmp: { 627 static Constant *LongjmpFCache = 0; 628 ReplaceCallWith("longjmp", CI, CI->op_begin()+1, CI->op_end(), 629 Type::VoidTy, LongjmpFCache); 630 break; 631 } 632 633 case Intrinsic::siglongjmp: { 634 // Insert the call to abort 635 static Constant *AbortFCache = 0; 636 ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(), 637 Type::VoidTy, AbortFCache); 638 break; 639 } 640 case Intrinsic::ctpop: 641 CI->replaceAllUsesWith(LowerCTPOP(CI->getOperand(1), CI)); 642 break; 643 644 case Intrinsic::bswap: 645 CI->replaceAllUsesWith(LowerBSWAP(CI->getOperand(1), CI)); 646 break; 647 648 case Intrinsic::ctlz: 649 CI->replaceAllUsesWith(LowerCTLZ(CI->getOperand(1), CI)); 650 break; 651 652 case Intrinsic::cttz: { 653 // cttz(x) -> ctpop(~X & (X-1)) 654 Value *Src = CI->getOperand(1); 655 Value *NotSrc = BinaryOperator::createNot(Src, Src->getName()+".not", CI); 656 Value *SrcM1 = ConstantInt::get(Src->getType(), 1); 657 SrcM1 = BinaryOperator::createSub(Src, SrcM1, "", CI); 658 Src = LowerCTPOP(BinaryOperator::createAnd(NotSrc, SrcM1, "", CI), CI); 659 CI->replaceAllUsesWith(Src); 660 break; 661 } 662 663 case Intrinsic::part_select: 664 CI->replaceAllUsesWith(LowerPartSelect(CI)); 665 break; 666 667 case Intrinsic::part_set: 668 CI->replaceAllUsesWith(LowerPartSet(CI)); 669 break; 670 671 case Intrinsic::stacksave: 672 case Intrinsic::stackrestore: { 673 static bool Warned = false; 674 if (!Warned) 675 cerr << "WARNING: this target does not support the llvm.stack" 676 << (Callee->getIntrinsicID() == Intrinsic::stacksave ? 677 "save" : "restore") << " intrinsic.\n"; 678 Warned = true; 679 if (Callee->getIntrinsicID() == Intrinsic::stacksave) 680 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 681 break; 682 } 683 684 case Intrinsic::returnaddress: 685 case Intrinsic::frameaddress: 686 cerr << "WARNING: this target does not support the llvm." 687 << (Callee->getIntrinsicID() == Intrinsic::returnaddress ? 688 "return" : "frame") << "address intrinsic.\n"; 689 CI->replaceAllUsesWith(ConstantPointerNull::get( 690 cast<PointerType>(CI->getType()))); 691 break; 692 693 case Intrinsic::prefetch: 694 break; // Simply strip out prefetches on unsupported architectures 695 696 case Intrinsic::pcmarker: 697 break; // Simply strip out pcmarker on unsupported architectures 698 case Intrinsic::readcyclecounter: { 699 cerr << "WARNING: this target does not support the llvm.readcyclecoun" 700 << "ter intrinsic. It is being lowered to a constant 0\n"; 701 CI->replaceAllUsesWith(ConstantInt::get(Type::Int64Ty, 0)); 702 break; 703 } 704 705 case Intrinsic::dbg_stoppoint: 706 case Intrinsic::dbg_region_start: 707 case Intrinsic::dbg_region_end: 708 case Intrinsic::dbg_func_start: 709 case Intrinsic::dbg_declare: 710 break; // Simply strip out debugging intrinsics 711 712 case Intrinsic::eh_exception: 713 case Intrinsic::eh_selector: 714 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 715 break; 716 717 case Intrinsic::eh_typeid_for: 718 // Return something different to eh_selector. 719 CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1)); 720 break; 721 722 case Intrinsic::var_annotation: 723 break; // Strip out annotate intrinsic 724 725 case Intrinsic::memcpy_i32: 726 case Intrinsic::memcpy_i64: { 727 static Constant *MemcpyFCache = 0; 728 Value *Size = CI->getOperand(3); 729 const Type *IntPtr = TD.getIntPtrType(); 730 if (Size->getType()->getPrimitiveSizeInBits() < 731 IntPtr->getPrimitiveSizeInBits()) 732 Size = new ZExtInst(Size, IntPtr, "", CI); 733 else if (Size->getType()->getPrimitiveSizeInBits() > 734 IntPtr->getPrimitiveSizeInBits()) 735 Size = new TruncInst(Size, IntPtr, "", CI); 736 Value *Ops[3]; 737 Ops[0] = CI->getOperand(1); 738 Ops[1] = CI->getOperand(2); 739 Ops[2] = Size; 740 ReplaceCallWith("memcpy", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 741 MemcpyFCache); 742 break; 743 } 744 case Intrinsic::memmove_i32: 745 case Intrinsic::memmove_i64: { 746 static Constant *MemmoveFCache = 0; 747 Value *Size = CI->getOperand(3); 748 const Type *IntPtr = TD.getIntPtrType(); 749 if (Size->getType()->getPrimitiveSizeInBits() < 750 IntPtr->getPrimitiveSizeInBits()) 751 Size = new ZExtInst(Size, IntPtr, "", CI); 752 else if (Size->getType()->getPrimitiveSizeInBits() > 753 IntPtr->getPrimitiveSizeInBits()) 754 Size = new TruncInst(Size, IntPtr, "", CI); 755 Value *Ops[3]; 756 Ops[0] = CI->getOperand(1); 757 Ops[1] = CI->getOperand(2); 758 Ops[2] = Size; 759 ReplaceCallWith("memmove", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 760 MemmoveFCache); 761 break; 762 } 763 case Intrinsic::memset_i32: 764 case Intrinsic::memset_i64: { 765 static Constant *MemsetFCache = 0; 766 Value *Size = CI->getOperand(3); 767 const Type *IntPtr = TD.getIntPtrType(); 768 if (Size->getType()->getPrimitiveSizeInBits() < 769 IntPtr->getPrimitiveSizeInBits()) 770 Size = new ZExtInst(Size, IntPtr, "", CI); 771 else if (Size->getType()->getPrimitiveSizeInBits() > 772 IntPtr->getPrimitiveSizeInBits()) 773 Size = new TruncInst(Size, IntPtr, "", CI); 774 Value *Ops[3]; 775 Ops[0] = CI->getOperand(1); 776 // Extend the amount to i32. 777 Ops[1] = new ZExtInst(CI->getOperand(2), Type::Int32Ty, "", CI); 778 Ops[2] = Size; 779 ReplaceCallWith("memset", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 780 MemsetFCache); 781 break; 782 } 783 case Intrinsic::sqrt_f32: { 784 static Constant *sqrtfFCache = 0; 785 ReplaceCallWith("sqrtf", CI, CI->op_begin()+1, CI->op_end(), 786 Type::FloatTy, sqrtfFCache); 787 break; 788 } 789 case Intrinsic::sqrt_f64: { 790 static Constant *sqrtFCache = 0; 791 ReplaceCallWith("sqrt", CI, CI->op_begin()+1, CI->op_end(), 792 Type::DoubleTy, sqrtFCache); 793 break; 794 } 795 } 796 797 assert(CI->use_empty() && 798 "Lowering should have eliminated any uses of the intrinsic call!"); 799 CI->eraseFromParent(); 800} 801