IntrinsicLowering.cpp revision f664e41b201bad27ed3661bf50cd71f54242c114
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" 23using namespace llvm; 24 25template <class ArgIt> 26static void EnsureFunctionExists(Module &M, const char *Name, 27 ArgIt ArgBegin, ArgIt ArgEnd, 28 const Type *RetTy) { 29 // Insert a correctly-typed definition now. 30 std::vector<const Type *> ParamTys; 31 for (ArgIt I = ArgBegin; I != ArgEnd; ++I) 32 ParamTys.push_back(I->getType()); 33 M.getOrInsertFunction(Name, FunctionType::get(RetTy, ParamTys, false)); 34} 35 36/// ReplaceCallWith - This function is used when we want to lower an intrinsic 37/// call to a call of an external function. This handles hard cases such as 38/// when there was already a prototype for the external function, and if that 39/// prototype doesn't match the arguments we expect to pass in. 40template <class ArgIt> 41static CallInst *ReplaceCallWith(const char *NewFn, CallInst *CI, 42 ArgIt ArgBegin, ArgIt ArgEnd, 43 const Type *RetTy, Constant *&FCache) { 44 if (!FCache) { 45 // If we haven't already looked up this function, check to see if the 46 // program already contains a function with this name. 47 Module *M = CI->getParent()->getParent()->getParent(); 48 // Get or insert the definition now. 49 std::vector<const Type *> ParamTys; 50 for (ArgIt I = ArgBegin; I != ArgEnd; ++I) 51 ParamTys.push_back((*I)->getType()); 52 FCache = M->getOrInsertFunction(NewFn, 53 FunctionType::get(RetTy, ParamTys, false)); 54 } 55 56 SmallVector<Value*, 8> Operands(ArgBegin, ArgEnd); 57 CallInst *NewCI = new CallInst(FCache, &Operands[0], Operands.size(), 58 CI->getName(), CI); 59 if (!CI->use_empty()) 60 CI->replaceAllUsesWith(NewCI); 61 return NewCI; 62} 63 64void IntrinsicLowering::AddPrototypes(Module &M) { 65 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) 66 if (I->isDeclaration() && !I->use_empty()) 67 switch (I->getIntrinsicID()) { 68 default: break; 69 case Intrinsic::setjmp: 70 EnsureFunctionExists(M, "setjmp", I->arg_begin(), I->arg_end(), 71 Type::Int32Ty); 72 break; 73 case Intrinsic::longjmp: 74 EnsureFunctionExists(M, "longjmp", I->arg_begin(), I->arg_end(), 75 Type::VoidTy); 76 break; 77 case Intrinsic::siglongjmp: 78 EnsureFunctionExists(M, "abort", I->arg_end(), I->arg_end(), 79 Type::VoidTy); 80 break; 81 case Intrinsic::memcpy_i32: 82 case Intrinsic::memcpy_i64: 83 M.getOrInsertFunction("memcpy", PointerType::get(Type::Int8Ty), 84 PointerType::get(Type::Int8Ty), 85 PointerType::get(Type::Int8Ty), 86 TD.getIntPtrType(), (Type *)0); 87 break; 88 case Intrinsic::memmove_i32: 89 case Intrinsic::memmove_i64: 90 M.getOrInsertFunction("memmove", PointerType::get(Type::Int8Ty), 91 PointerType::get(Type::Int8Ty), 92 PointerType::get(Type::Int8Ty), 93 TD.getIntPtrType(), (Type *)0); 94 break; 95 case Intrinsic::memset_i32: 96 case Intrinsic::memset_i64: 97 M.getOrInsertFunction("memset", PointerType::get(Type::Int8Ty), 98 PointerType::get(Type::Int8Ty), Type::Int32Ty, 99 TD.getIntPtrType(), (Type *)0); 100 break; 101 case Intrinsic::sqrt_f32: 102 case Intrinsic::sqrt_f64: 103 if(I->arg_begin()->getType() == Type::FloatTy) 104 EnsureFunctionExists(M, "sqrtf", I->arg_begin(), I->arg_end(), 105 Type::FloatTy); 106 else 107 EnsureFunctionExists(M, "sqrt", I->arg_begin(), I->arg_end(), 108 Type::DoubleTy); 109 break; 110 } 111} 112 113/// LowerBSWAP - Emit the code to lower bswap of V before the specified 114/// instruction IP. 115static Value *LowerBSWAP(Value *V, Instruction *IP) { 116 assert(V->getType()->isInteger() && "Can't bswap a non-integer type!"); 117 118 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 119 120 switch(BitSize) { 121 default: assert(0 && "Unhandled type size of value to byteswap!"); 122 case 16: { 123 Value *Tmp1 = BinaryOperator::createShl(V, 124 ConstantInt::get(V->getType(),8),"bswap.2",IP); 125 Value *Tmp2 = BinaryOperator::createLShr(V, 126 ConstantInt::get(V->getType(),8),"bswap.1",IP); 127 V = BinaryOperator::createOr(Tmp1, Tmp2, "bswap.i16", IP); 128 break; 129 } 130 case 32: { 131 Value *Tmp4 = BinaryOperator::createShl(V, 132 ConstantInt::get(V->getType(),24),"bswap.4", IP); 133 Value *Tmp3 = BinaryOperator::createShl(V, 134 ConstantInt::get(V->getType(),8),"bswap.3",IP); 135 Value *Tmp2 = BinaryOperator::createLShr(V, 136 ConstantInt::get(V->getType(),8),"bswap.2",IP); 137 Value *Tmp1 = BinaryOperator::createLShr(V, 138 ConstantInt::get(V->getType(),24),"bswap.1", IP); 139 Tmp3 = BinaryOperator::createAnd(Tmp3, 140 ConstantInt::get(Type::Int32Ty, 0xFF0000), 141 "bswap.and3", IP); 142 Tmp2 = BinaryOperator::createAnd(Tmp2, 143 ConstantInt::get(Type::Int32Ty, 0xFF00), 144 "bswap.and2", IP); 145 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp3, "bswap.or1", IP); 146 Tmp2 = BinaryOperator::createOr(Tmp2, Tmp1, "bswap.or2", IP); 147 V = BinaryOperator::createOr(Tmp4, Tmp2, "bswap.i32", IP); 148 break; 149 } 150 case 64: { 151 Value *Tmp8 = BinaryOperator::createShl(V, 152 ConstantInt::get(V->getType(),56),"bswap.8", IP); 153 Value *Tmp7 = BinaryOperator::createShl(V, 154 ConstantInt::get(V->getType(),40),"bswap.7", IP); 155 Value *Tmp6 = BinaryOperator::createShl(V, 156 ConstantInt::get(V->getType(),24),"bswap.6", IP); 157 Value *Tmp5 = BinaryOperator::createShl(V, 158 ConstantInt::get(V->getType(),8),"bswap.5", IP); 159 Value* Tmp4 = BinaryOperator::createLShr(V, 160 ConstantInt::get(V->getType(),8),"bswap.4", IP); 161 Value* Tmp3 = BinaryOperator::createLShr(V, 162 ConstantInt::get(V->getType(),24),"bswap.3", IP); 163 Value* Tmp2 = BinaryOperator::createLShr(V, 164 ConstantInt::get(V->getType(),40),"bswap.2", IP); 165 Value* Tmp1 = BinaryOperator::createLShr(V, 166 ConstantInt::get(V->getType(),56),"bswap.1", IP); 167 Tmp7 = BinaryOperator::createAnd(Tmp7, 168 ConstantInt::get(Type::Int64Ty, 169 0xFF000000000000ULL), 170 "bswap.and7", IP); 171 Tmp6 = BinaryOperator::createAnd(Tmp6, 172 ConstantInt::get(Type::Int64Ty, 0xFF0000000000ULL), 173 "bswap.and6", IP); 174 Tmp5 = BinaryOperator::createAnd(Tmp5, 175 ConstantInt::get(Type::Int64Ty, 0xFF00000000ULL), 176 "bswap.and5", IP); 177 Tmp4 = BinaryOperator::createAnd(Tmp4, 178 ConstantInt::get(Type::Int64Ty, 0xFF000000ULL), 179 "bswap.and4", IP); 180 Tmp3 = BinaryOperator::createAnd(Tmp3, 181 ConstantInt::get(Type::Int64Ty, 0xFF0000ULL), 182 "bswap.and3", IP); 183 Tmp2 = BinaryOperator::createAnd(Tmp2, 184 ConstantInt::get(Type::Int64Ty, 0xFF00ULL), 185 "bswap.and2", IP); 186 Tmp8 = BinaryOperator::createOr(Tmp8, Tmp7, "bswap.or1", IP); 187 Tmp6 = BinaryOperator::createOr(Tmp6, Tmp5, "bswap.or2", IP); 188 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp3, "bswap.or3", IP); 189 Tmp2 = BinaryOperator::createOr(Tmp2, Tmp1, "bswap.or4", IP); 190 Tmp8 = BinaryOperator::createOr(Tmp8, Tmp6, "bswap.or5", IP); 191 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp2, "bswap.or6", IP); 192 V = BinaryOperator::createOr(Tmp8, Tmp4, "bswap.i64", IP); 193 break; 194 } 195 } 196 return V; 197} 198 199/// LowerCTPOP - Emit the code to lower ctpop of V before the specified 200/// instruction IP. 201static Value *LowerCTPOP(Value *V, Instruction *IP) { 202 assert(V->getType()->isInteger() && "Can't ctpop a non-integer type!"); 203 204 static const uint64_t MaskValues[6] = { 205 0x5555555555555555ULL, 0x3333333333333333ULL, 206 0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL, 207 0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL 208 }; 209 210 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 211 unsigned WordSize = (BitSize + 63) / 64; 212 Value *Count = ConstantInt::get(V->getType(), 0); 213 214 for (unsigned n = 0; n < WordSize; ++n) { 215 Value *PartValue = V; 216 for (unsigned i = 1, ct = 0; i < (BitSize>64 ? 64 : BitSize); 217 i <<= 1, ++ct) { 218 Value *MaskCst = ConstantInt::get(V->getType(), MaskValues[ct]); 219 Value *LHS = BinaryOperator::createAnd( 220 PartValue, MaskCst, "cppop.and1", IP); 221 Value *VShift = BinaryOperator::createLShr(PartValue, 222 ConstantInt::get(V->getType(), i), "ctpop.sh", IP); 223 Value *RHS = BinaryOperator::createAnd(VShift, MaskCst, "cppop.and2", IP); 224 PartValue = BinaryOperator::createAdd(LHS, RHS, "ctpop.step", IP); 225 } 226 Count = BinaryOperator::createAdd(PartValue, Count, "ctpop.part", IP); 227 if (BitSize > 64) { 228 V = BinaryOperator::createLShr(V, ConstantInt::get(V->getType(), 64), 229 "ctpop.part.sh", IP); 230 BitSize -= 64; 231 } 232 } 233 234 return CastInst::createIntegerCast(Count, Type::Int32Ty, false, "ctpop", IP); 235} 236 237/// LowerCTLZ - Emit the code to lower ctlz of V before the specified 238/// instruction IP. 239static Value *LowerCTLZ(Value *V, Instruction *IP) { 240 241 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 242 for (unsigned i = 1; i < BitSize; i <<= 1) { 243 Value *ShVal = ConstantInt::get(V->getType(), i); 244 ShVal = BinaryOperator::createLShr(V, ShVal, "ctlz.sh", IP); 245 V = BinaryOperator::createOr(V, ShVal, "ctlz.step", IP); 246 } 247 248 V = BinaryOperator::createNot(V, "", IP); 249 return LowerCTPOP(V, IP); 250} 251 252/// Convert the llvm.part.select.iX.iY intrinsic. This intrinsic takes 253/// three integer arguments. The first argument is the Value from which the 254/// bits will be selected. It may be of any bit width. The second and third 255/// arguments specify a range of bits to select with the second argument 256/// specifying the low bit and the third argument specifying the high bit. Both 257/// must be type i32. The result is the corresponding selected bits from the 258/// Value in the same width as the Value (first argument). If the low bit index 259/// is higher than the high bit index then the inverse selection is done and 260/// the bits are returned in inverse order. 261/// @brief Lowering of llvm.part.select intrinsic. 262static Instruction *LowerPartSelect(CallInst *CI) { 263 // Make sure we're dealing with a part select intrinsic here 264 Function *F = CI->getCalledFunction(); 265 const FunctionType *FT = F->getFunctionType(); 266 if (!F->isDeclaration() || !FT->getReturnType()->isInteger() || 267 FT->getNumParams() != 3 || !FT->getParamType(0)->isInteger() || 268 !FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger()) 269 return CI; 270 271 // Get the intrinsic implementation function by converting all the . to _ 272 // in the intrinsic's function name and then reconstructing the function 273 // declaration. 274 std::string Name(F->getName()); 275 for (unsigned i = 4; i < Name.length(); ++i) 276 if (Name[i] == '.') 277 Name[i] = '_'; 278 Module* M = F->getParent(); 279 F = cast<Function>(M->getOrInsertFunction(Name, FT)); 280 F->setLinkage(GlobalValue::WeakLinkage); 281 282 // If we haven't defined the impl function yet, do so now 283 if (F->isDeclaration()) { 284 285 // Get the arguments to the function 286 Function::arg_iterator args = F->arg_begin(); 287 Value* Val = args++; Val->setName("Val"); 288 Value* Lo = args++; Lo->setName("Lo"); 289 Value* Hi = args++; Hi->setName("High"); 290 291 // We want to select a range of bits here such that [Hi, Lo] is shifted 292 // down to the low bits. However, it is quite possible that Hi is smaller 293 // than Lo in which case the bits have to be reversed. 294 295 // Create the blocks we will need for the two cases (forward, reverse) 296 BasicBlock* CurBB = new BasicBlock("entry", F); 297 BasicBlock *RevSize = new BasicBlock("revsize", CurBB->getParent()); 298 BasicBlock *FwdSize = new BasicBlock("fwdsize", CurBB->getParent()); 299 BasicBlock *Compute = new BasicBlock("compute", CurBB->getParent()); 300 BasicBlock *Reverse = new BasicBlock("reverse", CurBB->getParent()); 301 BasicBlock *RsltBlk = new BasicBlock("result", CurBB->getParent()); 302 303 // Cast Hi and Lo to the size of Val so the widths are all the same 304 if (Hi->getType() != Val->getType()) 305 Hi = CastInst::createIntegerCast(Hi, Val->getType(), false, 306 "tmp", CurBB); 307 if (Lo->getType() != Val->getType()) 308 Lo = CastInst::createIntegerCast(Lo, Val->getType(), false, 309 "tmp", CurBB); 310 311 // Compute a few things that both cases will need, up front. 312 Constant* Zero = ConstantInt::get(Val->getType(), 0); 313 Constant* One = ConstantInt::get(Val->getType(), 1); 314 Constant* AllOnes = ConstantInt::getAllOnesValue(Val->getType()); 315 316 // Compare the Hi and Lo bit positions. This is used to determine 317 // which case we have (forward or reverse) 318 ICmpInst *Cmp = new ICmpInst(ICmpInst::ICMP_ULT, Hi, Lo, "less",CurBB); 319 new BranchInst(RevSize, FwdSize, Cmp, CurBB); 320 321 // First, copmute the number of bits in the forward case. 322 Instruction* FBitSize = 323 BinaryOperator::createSub(Hi, Lo,"fbits", FwdSize); 324 new BranchInst(Compute, FwdSize); 325 326 // Second, compute the number of bits in the reverse case. 327 Instruction* RBitSize = 328 BinaryOperator::createSub(Lo, Hi, "rbits", RevSize); 329 new BranchInst(Compute, RevSize); 330 331 // Now, compute the bit range. Start by getting the bitsize and the shift 332 // amount (either Hi or Lo) from PHI nodes. Then we compute a mask for 333 // the number of bits we want in the range. We shift the bits down to the 334 // least significant bits, apply the mask to zero out unwanted high bits, 335 // and we have computed the "forward" result. It may still need to be 336 // reversed. 337 338 // Get the BitSize from one of the two subtractions 339 PHINode *BitSize = new PHINode(Val->getType(), "bits", Compute); 340 BitSize->reserveOperandSpace(2); 341 BitSize->addIncoming(FBitSize, FwdSize); 342 BitSize->addIncoming(RBitSize, RevSize); 343 344 // Get the ShiftAmount as the smaller of Hi/Lo 345 PHINode *ShiftAmt = new PHINode(Val->getType(), "shiftamt", Compute); 346 ShiftAmt->reserveOperandSpace(2); 347 ShiftAmt->addIncoming(Lo, FwdSize); 348 ShiftAmt->addIncoming(Hi, RevSize); 349 350 // Increment the bit size 351 Instruction *BitSizePlusOne = 352 BinaryOperator::createAdd(BitSize, One, "bits", Compute); 353 354 // Create a Mask to zero out the high order bits. 355 Instruction* Mask = 356 BinaryOperator::createShl(AllOnes, BitSizePlusOne, "mask", Compute); 357 Mask = BinaryOperator::createNot(Mask, "mask", Compute); 358 359 // Shift the bits down and apply the mask 360 Instruction* FRes = 361 BinaryOperator::createLShr(Val, ShiftAmt, "fres", Compute); 362 FRes = BinaryOperator::createAnd(FRes, Mask, "fres", Compute); 363 new BranchInst(Reverse, RsltBlk, Cmp, Compute); 364 365 // In the Reverse block we have the mask already in FRes but we must reverse 366 // it by shifting FRes bits right and putting them in RRes by shifting them 367 // in from left. 368 369 // First set up our loop counters 370 PHINode *Count = new PHINode(Val->getType(), "count", Reverse); 371 Count->reserveOperandSpace(2); 372 Count->addIncoming(BitSizePlusOne, Compute); 373 374 // Next, get the value that we are shifting. 375 PHINode *BitsToShift = new PHINode(Val->getType(), "val", Reverse); 376 BitsToShift->reserveOperandSpace(2); 377 BitsToShift->addIncoming(FRes, Compute); 378 379 // Finally, get the result of the last computation 380 PHINode *RRes = new PHINode(Val->getType(), "rres", Reverse); 381 RRes->reserveOperandSpace(2); 382 RRes->addIncoming(Zero, Compute); 383 384 // Decrement the counter 385 Instruction *Decr = BinaryOperator::createSub(Count, One, "decr", Reverse); 386 Count->addIncoming(Decr, Reverse); 387 388 // Compute the Bit that we want to move 389 Instruction *Bit = 390 BinaryOperator::createAnd(BitsToShift, One, "bit", Reverse); 391 392 // Compute the new value for next iteration. 393 Instruction *NewVal = 394 BinaryOperator::createLShr(BitsToShift, One, "rshift", Reverse); 395 BitsToShift->addIncoming(NewVal, Reverse); 396 397 // Shift the bit into the low bits of the result. 398 Instruction *NewRes = 399 BinaryOperator::createShl(RRes, One, "lshift", Reverse); 400 NewRes = BinaryOperator::createOr(NewRes, Bit, "addbit", Reverse); 401 RRes->addIncoming(NewRes, Reverse); 402 403 // Terminate loop if we've moved all the bits. 404 ICmpInst *Cond = 405 new ICmpInst(ICmpInst::ICMP_EQ, Decr, Zero, "cond", Reverse); 406 new BranchInst(RsltBlk, Reverse, Cond, Reverse); 407 408 // Finally, in the result block, select one of the two results with a PHI 409 // node and return the result; 410 CurBB = RsltBlk; 411 PHINode *BitSelect = new PHINode(Val->getType(), "part_select", CurBB); 412 BitSelect->reserveOperandSpace(2); 413 BitSelect->addIncoming(FRes, Compute); 414 BitSelect->addIncoming(NewRes, Reverse); 415 new ReturnInst(BitSelect, CurBB); 416 } 417 418 // Return a call to the implementation function 419 Value *Args[] = { 420 CI->getOperand(1), 421 CI->getOperand(2), 422 CI->getOperand(3) 423 }; 424 return new CallInst(F, Args, sizeof(Args)/sizeof(Args[0]), CI->getName(), CI); 425} 426 427/// Convert the llvm.part.set.iX.iY.iZ intrinsic. This intrinsic takes 428/// four integer arguments (iAny %Value, iAny %Replacement, i32 %Low, i32 %High) 429/// The first two arguments can be any bit width. The result is the same width 430/// as %Value. The operation replaces bits between %Low and %High with the value 431/// in %Replacement. If %Replacement is not the same width, it is truncated or 432/// zero extended as appropriate to fit the bits being replaced. If %Low is 433/// greater than %High then the inverse set of bits are replaced. 434/// @brief Lowering of llvm.bit.part.set intrinsic. 435static Instruction *LowerPartSet(CallInst *CI) { 436 // Make sure we're dealing with a part select intrinsic here 437 Function *F = CI->getCalledFunction(); 438 const FunctionType *FT = F->getFunctionType(); 439 if (!F->isDeclaration() || !FT->getReturnType()->isInteger() || 440 FT->getNumParams() != 4 || !FT->getParamType(0)->isInteger() || 441 !FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger() || 442 !FT->getParamType(3)->isInteger()) 443 return CI; 444 445 // Get the intrinsic implementation function by converting all the . to _ 446 // in the intrinsic's function name and then reconstructing the function 447 // declaration. 448 std::string Name(F->getName()); 449 for (unsigned i = 4; i < Name.length(); ++i) 450 if (Name[i] == '.') 451 Name[i] = '_'; 452 Module* M = F->getParent(); 453 F = cast<Function>(M->getOrInsertFunction(Name, FT)); 454 F->setLinkage(GlobalValue::WeakLinkage); 455 456 // If we haven't defined the impl function yet, do so now 457 if (F->isDeclaration()) { 458 // Get the arguments for the function. 459 Function::arg_iterator args = F->arg_begin(); 460 Value* Val = args++; Val->setName("Val"); 461 Value* Rep = args++; Rep->setName("Rep"); 462 Value* Lo = args++; Lo->setName("Lo"); 463 Value* Hi = args++; Hi->setName("Hi"); 464 465 // Get some types we need 466 const IntegerType* ValTy = cast<IntegerType>(Val->getType()); 467 const IntegerType* RepTy = cast<IntegerType>(Rep->getType()); 468 uint32_t ValBits = ValTy->getBitWidth(); 469 uint32_t RepBits = RepTy->getBitWidth(); 470 471 // Constant Definitions 472 ConstantInt* RepBitWidth = ConstantInt::get(Type::Int32Ty, RepBits); 473 ConstantInt* RepMask = ConstantInt::getAllOnesValue(RepTy); 474 ConstantInt* ValMask = ConstantInt::getAllOnesValue(ValTy); 475 ConstantInt* One = ConstantInt::get(Type::Int32Ty, 1); 476 ConstantInt* ValOne = ConstantInt::get(ValTy, 1); 477 ConstantInt* Zero = ConstantInt::get(Type::Int32Ty, 0); 478 ConstantInt* ValZero = ConstantInt::get(ValTy, 0); 479 480 // Basic blocks we fill in below. 481 BasicBlock* entry = new BasicBlock("entry", F, 0); 482 BasicBlock* large = new BasicBlock("large", F, 0); 483 BasicBlock* small = new BasicBlock("small", F, 0); 484 BasicBlock* reverse = new BasicBlock("reverse", F, 0); 485 BasicBlock* result = new BasicBlock("result", F, 0); 486 487 // BASIC BLOCK: entry 488 // First, get the number of bits that we're placing as an i32 489 ICmpInst* is_forward = 490 new ICmpInst(ICmpInst::ICMP_ULT, Lo, Hi, "", entry); 491 SelectInst* Hi_pn = new SelectInst(is_forward, Hi, Lo, "", entry); 492 SelectInst* Lo_pn = new SelectInst(is_forward, Lo, Hi, "", entry); 493 BinaryOperator* NumBits = BinaryOperator::createSub(Hi_pn, Lo_pn, "",entry); 494 NumBits = BinaryOperator::createAdd(NumBits, One, "", entry); 495 // Now, convert Lo and Hi to ValTy bit width 496 if (ValBits > 32) { 497 Lo = new ZExtInst(Lo_pn, ValTy, "", entry); 498 } else if (ValBits < 32) { 499 Lo = new TruncInst(Lo_pn, ValTy, "", entry); 500 } 501 // Determine if the replacement bits are larger than the number of bits we 502 // are replacing and deal with it. 503 ICmpInst* is_large = 504 new ICmpInst(ICmpInst::ICMP_ULT, NumBits, RepBitWidth, "", entry); 505 new BranchInst(large, small, is_large, entry); 506 507 // BASIC BLOCK: large 508 Instruction* MaskBits = 509 BinaryOperator::createSub(RepBitWidth, NumBits, "", large); 510 MaskBits = CastInst::createIntegerCast(MaskBits, RepMask->getType(), 511 false, "", large); 512 BinaryOperator* Mask1 = 513 BinaryOperator::createLShr(RepMask, MaskBits, "", large); 514 BinaryOperator* Rep2 = BinaryOperator::createAnd(Mask1, Rep, "", large); 515 new BranchInst(small, large); 516 517 // BASIC BLOCK: small 518 PHINode* Rep3 = new PHINode(RepTy, "", small); 519 Rep3->reserveOperandSpace(2); 520 Rep3->addIncoming(Rep2, large); 521 Rep3->addIncoming(Rep, entry); 522 Value* Rep4 = Rep3; 523 if (ValBits > RepBits) 524 Rep4 = new ZExtInst(Rep3, ValTy, "", small); 525 else if (ValBits < RepBits) 526 Rep4 = new TruncInst(Rep3, ValTy, "", small); 527 new BranchInst(result, reverse, is_forward, small); 528 529 // BASIC BLOCK: reverse (reverses the bits of the replacement) 530 // Set up our loop counter as a PHI so we can decrement on each iteration. 531 // We will loop for the number of bits in the replacement value. 532 PHINode *Count = new PHINode(Type::Int32Ty, "count", reverse); 533 Count->reserveOperandSpace(2); 534 Count->addIncoming(NumBits, small); 535 536 // Get the value that we are shifting bits out of as a PHI because 537 // we'll change this with each iteration. 538 PHINode *BitsToShift = new PHINode(Val->getType(), "val", reverse); 539 BitsToShift->reserveOperandSpace(2); 540 BitsToShift->addIncoming(Rep4, small); 541 542 // Get the result of the last computation or zero on first iteration 543 PHINode *RRes = new PHINode(Val->getType(), "rres", reverse); 544 RRes->reserveOperandSpace(2); 545 RRes->addIncoming(ValZero, small); 546 547 // Decrement the loop counter by one 548 Instruction *Decr = BinaryOperator::createSub(Count, One, "", reverse); 549 Count->addIncoming(Decr, reverse); 550 551 // Get the bit that we want to move into the result 552 Value *Bit = BinaryOperator::createAnd(BitsToShift, ValOne, "", reverse); 553 554 // Compute the new value of the bits to shift for the next iteration. 555 Value *NewVal = BinaryOperator::createLShr(BitsToShift, ValOne,"", reverse); 556 BitsToShift->addIncoming(NewVal, reverse); 557 558 // Shift the bit we extracted into the low bit of the result. 559 Instruction *NewRes = BinaryOperator::createShl(RRes, ValOne, "", reverse); 560 NewRes = BinaryOperator::createOr(NewRes, Bit, "", reverse); 561 RRes->addIncoming(NewRes, reverse); 562 563 // Terminate loop if we've moved all the bits. 564 ICmpInst *Cond = new ICmpInst(ICmpInst::ICMP_EQ, Decr, Zero, "", reverse); 565 new BranchInst(result, reverse, Cond, reverse); 566 567 // BASIC BLOCK: result 568 PHINode *Rplcmnt = new PHINode(Val->getType(), "", result); 569 Rplcmnt->reserveOperandSpace(2); 570 Rplcmnt->addIncoming(NewRes, reverse); 571 Rplcmnt->addIncoming(Rep4, small); 572 Value* t0 = CastInst::createIntegerCast(NumBits,ValTy,false,"",result); 573 Value* t1 = BinaryOperator::createShl(ValMask, Lo, "", result); 574 Value* t2 = BinaryOperator::createNot(t1, "", result); 575 Value* t3 = BinaryOperator::createShl(t1, t0, "", result); 576 Value* t4 = BinaryOperator::createOr(t2, t3, "", result); 577 Value* t5 = BinaryOperator::createAnd(t4, Val, "", result); 578 Value* t6 = BinaryOperator::createShl(Rplcmnt, Lo, "", result); 579 Value* Rslt = BinaryOperator::createOr(t5, t6, "part_set", result); 580 new ReturnInst(Rslt, result); 581 } 582 583 // Return a call to the implementation function 584 Value *Args[] = { 585 CI->getOperand(1), 586 CI->getOperand(2), 587 CI->getOperand(3), 588 CI->getOperand(4) 589 }; 590 return new CallInst(F, Args, sizeof(Args)/sizeof(Args[0]), CI->getName(), CI); 591} 592 593 594void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) { 595 Function *Callee = CI->getCalledFunction(); 596 assert(Callee && "Cannot lower an indirect call!"); 597 598 switch (Callee->getIntrinsicID()) { 599 case Intrinsic::not_intrinsic: 600 cerr << "Cannot lower a call to a non-intrinsic function '" 601 << Callee->getName() << "'!\n"; 602 abort(); 603 default: 604 cerr << "Error: Code generator does not support intrinsic function '" 605 << Callee->getName() << "'!\n"; 606 abort(); 607 608 // The setjmp/longjmp intrinsics should only exist in the code if it was 609 // never optimized (ie, right out of the CFE), or if it has been hacked on 610 // by the lowerinvoke pass. In both cases, the right thing to do is to 611 // convert the call to an explicit setjmp or longjmp call. 612 case Intrinsic::setjmp: { 613 static Constant *SetjmpFCache = 0; 614 Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin()+1, CI->op_end(), 615 Type::Int32Ty, SetjmpFCache); 616 if (CI->getType() != Type::VoidTy) 617 CI->replaceAllUsesWith(V); 618 break; 619 } 620 case Intrinsic::sigsetjmp: 621 if (CI->getType() != Type::VoidTy) 622 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 623 break; 624 625 case Intrinsic::longjmp: { 626 static Constant *LongjmpFCache = 0; 627 ReplaceCallWith("longjmp", CI, CI->op_begin()+1, CI->op_end(), 628 Type::VoidTy, LongjmpFCache); 629 break; 630 } 631 632 case Intrinsic::siglongjmp: { 633 // Insert the call to abort 634 static Constant *AbortFCache = 0; 635 ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(), 636 Type::VoidTy, AbortFCache); 637 break; 638 } 639 case Intrinsic::ctpop: 640 CI->replaceAllUsesWith(LowerCTPOP(CI->getOperand(1), CI)); 641 break; 642 643 case Intrinsic::bswap: 644 CI->replaceAllUsesWith(LowerBSWAP(CI->getOperand(1), CI)); 645 break; 646 647 case Intrinsic::ctlz: 648 CI->replaceAllUsesWith(LowerCTLZ(CI->getOperand(1), CI)); 649 break; 650 651 case Intrinsic::cttz: { 652 // cttz(x) -> ctpop(~X & (X-1)) 653 Value *Src = CI->getOperand(1); 654 Value *NotSrc = BinaryOperator::createNot(Src, Src->getName()+".not", CI); 655 Value *SrcM1 = ConstantInt::get(Src->getType(), 1); 656 SrcM1 = BinaryOperator::createSub(Src, SrcM1, "", CI); 657 Src = LowerCTPOP(BinaryOperator::createAnd(NotSrc, SrcM1, "", CI), CI); 658 CI->replaceAllUsesWith(Src); 659 break; 660 } 661 662 case Intrinsic::part_select: 663 CI->replaceAllUsesWith(LowerPartSelect(CI)); 664 break; 665 666 case Intrinsic::part_set: 667 CI->replaceAllUsesWith(LowerPartSet(CI)); 668 break; 669 670 case Intrinsic::stacksave: 671 case Intrinsic::stackrestore: { 672 static bool Warned = false; 673 if (!Warned) 674 cerr << "WARNING: this target does not support the llvm.stack" 675 << (Callee->getIntrinsicID() == Intrinsic::stacksave ? 676 "save" : "restore") << " intrinsic.\n"; 677 Warned = true; 678 if (Callee->getIntrinsicID() == Intrinsic::stacksave) 679 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 680 break; 681 } 682 683 case Intrinsic::returnaddress: 684 case Intrinsic::frameaddress: 685 cerr << "WARNING: this target does not support the llvm." 686 << (Callee->getIntrinsicID() == Intrinsic::returnaddress ? 687 "return" : "frame") << "address intrinsic.\n"; 688 CI->replaceAllUsesWith(ConstantPointerNull::get( 689 cast<PointerType>(CI->getType()))); 690 break; 691 692 case Intrinsic::prefetch: 693 break; // Simply strip out prefetches on unsupported architectures 694 695 case Intrinsic::pcmarker: 696 break; // Simply strip out pcmarker on unsupported architectures 697 case Intrinsic::readcyclecounter: { 698 cerr << "WARNING: this target does not support the llvm.readcyclecoun" 699 << "ter intrinsic. It is being lowered to a constant 0\n"; 700 CI->replaceAllUsesWith(ConstantInt::get(Type::Int64Ty, 0)); 701 break; 702 } 703 704 case Intrinsic::dbg_stoppoint: 705 case Intrinsic::dbg_region_start: 706 case Intrinsic::dbg_region_end: 707 case Intrinsic::dbg_func_start: 708 case Intrinsic::dbg_declare: 709 break; // Simply strip out debugging intrinsics 710 711 case Intrinsic::eh_exception: 712 case Intrinsic::eh_selector: 713 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 714 break; 715 716 case Intrinsic::eh_typeid_for: 717 // Return something different to eh_selector. 718 CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1)); 719 break; 720 721 case Intrinsic::var_annotation: 722 break; // Strip out annotate intrinsic 723 724 case Intrinsic::memcpy_i32: 725 case Intrinsic::memcpy_i64: { 726 static Constant *MemcpyFCache = 0; 727 Value *Size = CI->getOperand(3); 728 const Type *IntPtr = TD.getIntPtrType(); 729 if (Size->getType()->getPrimitiveSizeInBits() < 730 IntPtr->getPrimitiveSizeInBits()) 731 Size = new ZExtInst(Size, IntPtr, "", CI); 732 else if (Size->getType()->getPrimitiveSizeInBits() > 733 IntPtr->getPrimitiveSizeInBits()) 734 Size = new TruncInst(Size, IntPtr, "", CI); 735 Value *Ops[3]; 736 Ops[0] = CI->getOperand(1); 737 Ops[1] = CI->getOperand(2); 738 Ops[2] = Size; 739 ReplaceCallWith("memcpy", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 740 MemcpyFCache); 741 break; 742 } 743 case Intrinsic::memmove_i32: 744 case Intrinsic::memmove_i64: { 745 static Constant *MemmoveFCache = 0; 746 Value *Size = CI->getOperand(3); 747 const Type *IntPtr = TD.getIntPtrType(); 748 if (Size->getType()->getPrimitiveSizeInBits() < 749 IntPtr->getPrimitiveSizeInBits()) 750 Size = new ZExtInst(Size, IntPtr, "", CI); 751 else if (Size->getType()->getPrimitiveSizeInBits() > 752 IntPtr->getPrimitiveSizeInBits()) 753 Size = new TruncInst(Size, IntPtr, "", CI); 754 Value *Ops[3]; 755 Ops[0] = CI->getOperand(1); 756 Ops[1] = CI->getOperand(2); 757 Ops[2] = Size; 758 ReplaceCallWith("memmove", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 759 MemmoveFCache); 760 break; 761 } 762 case Intrinsic::memset_i32: 763 case Intrinsic::memset_i64: { 764 static Constant *MemsetFCache = 0; 765 Value *Size = CI->getOperand(3); 766 const Type *IntPtr = TD.getIntPtrType(); 767 if (Size->getType()->getPrimitiveSizeInBits() < 768 IntPtr->getPrimitiveSizeInBits()) 769 Size = new ZExtInst(Size, IntPtr, "", CI); 770 else if (Size->getType()->getPrimitiveSizeInBits() > 771 IntPtr->getPrimitiveSizeInBits()) 772 Size = new TruncInst(Size, IntPtr, "", CI); 773 Value *Ops[3]; 774 Ops[0] = CI->getOperand(1); 775 // Extend the amount to i32. 776 Ops[1] = new ZExtInst(CI->getOperand(2), Type::Int32Ty, "", CI); 777 Ops[2] = Size; 778 ReplaceCallWith("memset", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 779 MemsetFCache); 780 break; 781 } 782 case Intrinsic::sqrt_f32: { 783 static Constant *sqrtfFCache = 0; 784 ReplaceCallWith("sqrtf", CI, CI->op_begin()+1, CI->op_end(), 785 Type::FloatTy, sqrtfFCache); 786 break; 787 } 788 case Intrinsic::sqrt_f64: { 789 static Constant *sqrtFCache = 0; 790 ReplaceCallWith("sqrt", CI, CI->op_begin()+1, CI->op_end(), 791 Type::DoubleTy, sqrtFCache); 792 break; 793 } 794 } 795 796 assert(CI->use_empty() && 797 "Lowering should have eliminated any uses of the intrinsic call!"); 798 CI->eraseFromParent(); 799} 800