IntrinsicLowering.cpp revision 9ab7fb3ba47442d521a5bed09a27a5e8e7a786ed
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: 103 switch((int)I->arg_begin()->getType()->getTypeID()) { 104 case Type::FloatTyID: 105 EnsureFunctionExists(M, "sqrtf", I->arg_begin(), I->arg_end(), 106 Type::FloatTy); 107 case Type::DoubleTyID: 108 EnsureFunctionExists(M, "sqrt", I->arg_begin(), I->arg_end(), 109 Type::DoubleTy); 110 case Type::X86_FP80TyID: 111 case Type::FP128TyID: 112 case Type::PPC_FP128TyID: 113 EnsureFunctionExists(M, "sqrtl", I->arg_begin(), I->arg_end(), 114 I->arg_begin()->getType()); 115 } 116 break; 117 } 118} 119 120/// LowerBSWAP - Emit the code to lower bswap of V before the specified 121/// instruction IP. 122static Value *LowerBSWAP(Value *V, Instruction *IP) { 123 assert(V->getType()->isInteger() && "Can't bswap a non-integer type!"); 124 125 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 126 127 switch(BitSize) { 128 default: assert(0 && "Unhandled type size of value to byteswap!"); 129 case 16: { 130 Value *Tmp1 = BinaryOperator::createShl(V, 131 ConstantInt::get(V->getType(),8),"bswap.2",IP); 132 Value *Tmp2 = BinaryOperator::createLShr(V, 133 ConstantInt::get(V->getType(),8),"bswap.1",IP); 134 V = BinaryOperator::createOr(Tmp1, Tmp2, "bswap.i16", IP); 135 break; 136 } 137 case 32: { 138 Value *Tmp4 = BinaryOperator::createShl(V, 139 ConstantInt::get(V->getType(),24),"bswap.4", IP); 140 Value *Tmp3 = BinaryOperator::createShl(V, 141 ConstantInt::get(V->getType(),8),"bswap.3",IP); 142 Value *Tmp2 = BinaryOperator::createLShr(V, 143 ConstantInt::get(V->getType(),8),"bswap.2",IP); 144 Value *Tmp1 = BinaryOperator::createLShr(V, 145 ConstantInt::get(V->getType(),24),"bswap.1", IP); 146 Tmp3 = BinaryOperator::createAnd(Tmp3, 147 ConstantInt::get(Type::Int32Ty, 0xFF0000), 148 "bswap.and3", IP); 149 Tmp2 = BinaryOperator::createAnd(Tmp2, 150 ConstantInt::get(Type::Int32Ty, 0xFF00), 151 "bswap.and2", IP); 152 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp3, "bswap.or1", IP); 153 Tmp2 = BinaryOperator::createOr(Tmp2, Tmp1, "bswap.or2", IP); 154 V = BinaryOperator::createOr(Tmp4, Tmp2, "bswap.i32", IP); 155 break; 156 } 157 case 64: { 158 Value *Tmp8 = BinaryOperator::createShl(V, 159 ConstantInt::get(V->getType(),56),"bswap.8", IP); 160 Value *Tmp7 = BinaryOperator::createShl(V, 161 ConstantInt::get(V->getType(),40),"bswap.7", IP); 162 Value *Tmp6 = BinaryOperator::createShl(V, 163 ConstantInt::get(V->getType(),24),"bswap.6", IP); 164 Value *Tmp5 = BinaryOperator::createShl(V, 165 ConstantInt::get(V->getType(),8),"bswap.5", IP); 166 Value* Tmp4 = BinaryOperator::createLShr(V, 167 ConstantInt::get(V->getType(),8),"bswap.4", IP); 168 Value* Tmp3 = BinaryOperator::createLShr(V, 169 ConstantInt::get(V->getType(),24),"bswap.3", IP); 170 Value* Tmp2 = BinaryOperator::createLShr(V, 171 ConstantInt::get(V->getType(),40),"bswap.2", IP); 172 Value* Tmp1 = BinaryOperator::createLShr(V, 173 ConstantInt::get(V->getType(),56),"bswap.1", IP); 174 Tmp7 = BinaryOperator::createAnd(Tmp7, 175 ConstantInt::get(Type::Int64Ty, 176 0xFF000000000000ULL), 177 "bswap.and7", IP); 178 Tmp6 = BinaryOperator::createAnd(Tmp6, 179 ConstantInt::get(Type::Int64Ty, 0xFF0000000000ULL), 180 "bswap.and6", IP); 181 Tmp5 = BinaryOperator::createAnd(Tmp5, 182 ConstantInt::get(Type::Int64Ty, 0xFF00000000ULL), 183 "bswap.and5", IP); 184 Tmp4 = BinaryOperator::createAnd(Tmp4, 185 ConstantInt::get(Type::Int64Ty, 0xFF000000ULL), 186 "bswap.and4", IP); 187 Tmp3 = BinaryOperator::createAnd(Tmp3, 188 ConstantInt::get(Type::Int64Ty, 0xFF0000ULL), 189 "bswap.and3", IP); 190 Tmp2 = BinaryOperator::createAnd(Tmp2, 191 ConstantInt::get(Type::Int64Ty, 0xFF00ULL), 192 "bswap.and2", IP); 193 Tmp8 = BinaryOperator::createOr(Tmp8, Tmp7, "bswap.or1", IP); 194 Tmp6 = BinaryOperator::createOr(Tmp6, Tmp5, "bswap.or2", IP); 195 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp3, "bswap.or3", IP); 196 Tmp2 = BinaryOperator::createOr(Tmp2, Tmp1, "bswap.or4", IP); 197 Tmp8 = BinaryOperator::createOr(Tmp8, Tmp6, "bswap.or5", IP); 198 Tmp4 = BinaryOperator::createOr(Tmp4, Tmp2, "bswap.or6", IP); 199 V = BinaryOperator::createOr(Tmp8, Tmp4, "bswap.i64", IP); 200 break; 201 } 202 } 203 return V; 204} 205 206/// LowerCTPOP - Emit the code to lower ctpop of V before the specified 207/// instruction IP. 208static Value *LowerCTPOP(Value *V, Instruction *IP) { 209 assert(V->getType()->isInteger() && "Can't ctpop a non-integer type!"); 210 211 static const uint64_t MaskValues[6] = { 212 0x5555555555555555ULL, 0x3333333333333333ULL, 213 0x0F0F0F0F0F0F0F0FULL, 0x00FF00FF00FF00FFULL, 214 0x0000FFFF0000FFFFULL, 0x00000000FFFFFFFFULL 215 }; 216 217 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 218 unsigned WordSize = (BitSize + 63) / 64; 219 Value *Count = ConstantInt::get(V->getType(), 0); 220 221 for (unsigned n = 0; n < WordSize; ++n) { 222 Value *PartValue = V; 223 for (unsigned i = 1, ct = 0; i < (BitSize>64 ? 64 : BitSize); 224 i <<= 1, ++ct) { 225 Value *MaskCst = ConstantInt::get(V->getType(), MaskValues[ct]); 226 Value *LHS = BinaryOperator::createAnd( 227 PartValue, MaskCst, "cppop.and1", IP); 228 Value *VShift = BinaryOperator::createLShr(PartValue, 229 ConstantInt::get(V->getType(), i), "ctpop.sh", IP); 230 Value *RHS = BinaryOperator::createAnd(VShift, MaskCst, "cppop.and2", IP); 231 PartValue = BinaryOperator::createAdd(LHS, RHS, "ctpop.step", IP); 232 } 233 Count = BinaryOperator::createAdd(PartValue, Count, "ctpop.part", IP); 234 if (BitSize > 64) { 235 V = BinaryOperator::createLShr(V, ConstantInt::get(V->getType(), 64), 236 "ctpop.part.sh", IP); 237 BitSize -= 64; 238 } 239 } 240 241 return Count; 242} 243 244/// LowerCTLZ - Emit the code to lower ctlz of V before the specified 245/// instruction IP. 246static Value *LowerCTLZ(Value *V, Instruction *IP) { 247 248 unsigned BitSize = V->getType()->getPrimitiveSizeInBits(); 249 for (unsigned i = 1; i < BitSize; i <<= 1) { 250 Value *ShVal = ConstantInt::get(V->getType(), i); 251 ShVal = BinaryOperator::createLShr(V, ShVal, "ctlz.sh", IP); 252 V = BinaryOperator::createOr(V, ShVal, "ctlz.step", IP); 253 } 254 255 V = BinaryOperator::createNot(V, "", IP); 256 return LowerCTPOP(V, IP); 257} 258 259/// Convert the llvm.part.select.iX.iY intrinsic. This intrinsic takes 260/// three integer arguments. The first argument is the Value from which the 261/// bits will be selected. It may be of any bit width. The second and third 262/// arguments specify a range of bits to select with the second argument 263/// specifying the low bit and the third argument specifying the high bit. Both 264/// must be type i32. The result is the corresponding selected bits from the 265/// Value in the same width as the Value (first argument). If the low bit index 266/// is higher than the high bit index then the inverse selection is done and 267/// the bits are returned in inverse order. 268/// @brief Lowering of llvm.part.select intrinsic. 269static Instruction *LowerPartSelect(CallInst *CI) { 270 // Make sure we're dealing with a part select intrinsic here 271 Function *F = CI->getCalledFunction(); 272 const FunctionType *FT = F->getFunctionType(); 273 if (!F->isDeclaration() || !FT->getReturnType()->isInteger() || 274 FT->getNumParams() != 3 || !FT->getParamType(0)->isInteger() || 275 !FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger()) 276 return CI; 277 278 // Get the intrinsic implementation function by converting all the . to _ 279 // in the intrinsic's function name and then reconstructing the function 280 // declaration. 281 std::string Name(F->getName()); 282 for (unsigned i = 4; i < Name.length(); ++i) 283 if (Name[i] == '.') 284 Name[i] = '_'; 285 Module* M = F->getParent(); 286 F = cast<Function>(M->getOrInsertFunction(Name, FT)); 287 F->setLinkage(GlobalValue::WeakLinkage); 288 289 // If we haven't defined the impl function yet, do so now 290 if (F->isDeclaration()) { 291 292 // Get the arguments to the function 293 Function::arg_iterator args = F->arg_begin(); 294 Value* Val = args++; Val->setName("Val"); 295 Value* Lo = args++; Lo->setName("Lo"); 296 Value* Hi = args++; Hi->setName("High"); 297 298 // We want to select a range of bits here such that [Hi, Lo] is shifted 299 // down to the low bits. However, it is quite possible that Hi is smaller 300 // than Lo in which case the bits have to be reversed. 301 302 // Create the blocks we will need for the two cases (forward, reverse) 303 BasicBlock* CurBB = new BasicBlock("entry", F); 304 BasicBlock *RevSize = new BasicBlock("revsize", CurBB->getParent()); 305 BasicBlock *FwdSize = new BasicBlock("fwdsize", CurBB->getParent()); 306 BasicBlock *Compute = new BasicBlock("compute", CurBB->getParent()); 307 BasicBlock *Reverse = new BasicBlock("reverse", CurBB->getParent()); 308 BasicBlock *RsltBlk = new BasicBlock("result", CurBB->getParent()); 309 310 // Cast Hi and Lo to the size of Val so the widths are all the same 311 if (Hi->getType() != Val->getType()) 312 Hi = CastInst::createIntegerCast(Hi, Val->getType(), false, 313 "tmp", CurBB); 314 if (Lo->getType() != Val->getType()) 315 Lo = CastInst::createIntegerCast(Lo, Val->getType(), false, 316 "tmp", CurBB); 317 318 // Compute a few things that both cases will need, up front. 319 Constant* Zero = ConstantInt::get(Val->getType(), 0); 320 Constant* One = ConstantInt::get(Val->getType(), 1); 321 Constant* AllOnes = ConstantInt::getAllOnesValue(Val->getType()); 322 323 // Compare the Hi and Lo bit positions. This is used to determine 324 // which case we have (forward or reverse) 325 ICmpInst *Cmp = new ICmpInst(ICmpInst::ICMP_ULT, Hi, Lo, "less",CurBB); 326 new BranchInst(RevSize, FwdSize, Cmp, CurBB); 327 328 // First, copmute the number of bits in the forward case. 329 Instruction* FBitSize = 330 BinaryOperator::createSub(Hi, Lo,"fbits", FwdSize); 331 new BranchInst(Compute, FwdSize); 332 333 // Second, compute the number of bits in the reverse case. 334 Instruction* RBitSize = 335 BinaryOperator::createSub(Lo, Hi, "rbits", RevSize); 336 new BranchInst(Compute, RevSize); 337 338 // Now, compute the bit range. Start by getting the bitsize and the shift 339 // amount (either Hi or Lo) from PHI nodes. Then we compute a mask for 340 // the number of bits we want in the range. We shift the bits down to the 341 // least significant bits, apply the mask to zero out unwanted high bits, 342 // and we have computed the "forward" result. It may still need to be 343 // reversed. 344 345 // Get the BitSize from one of the two subtractions 346 PHINode *BitSize = new PHINode(Val->getType(), "bits", Compute); 347 BitSize->reserveOperandSpace(2); 348 BitSize->addIncoming(FBitSize, FwdSize); 349 BitSize->addIncoming(RBitSize, RevSize); 350 351 // Get the ShiftAmount as the smaller of Hi/Lo 352 PHINode *ShiftAmt = new PHINode(Val->getType(), "shiftamt", Compute); 353 ShiftAmt->reserveOperandSpace(2); 354 ShiftAmt->addIncoming(Lo, FwdSize); 355 ShiftAmt->addIncoming(Hi, RevSize); 356 357 // Increment the bit size 358 Instruction *BitSizePlusOne = 359 BinaryOperator::createAdd(BitSize, One, "bits", Compute); 360 361 // Create a Mask to zero out the high order bits. 362 Instruction* Mask = 363 BinaryOperator::createShl(AllOnes, BitSizePlusOne, "mask", Compute); 364 Mask = BinaryOperator::createNot(Mask, "mask", Compute); 365 366 // Shift the bits down and apply the mask 367 Instruction* FRes = 368 BinaryOperator::createLShr(Val, ShiftAmt, "fres", Compute); 369 FRes = BinaryOperator::createAnd(FRes, Mask, "fres", Compute); 370 new BranchInst(Reverse, RsltBlk, Cmp, Compute); 371 372 // In the Reverse block we have the mask already in FRes but we must reverse 373 // it by shifting FRes bits right and putting them in RRes by shifting them 374 // in from left. 375 376 // First set up our loop counters 377 PHINode *Count = new PHINode(Val->getType(), "count", Reverse); 378 Count->reserveOperandSpace(2); 379 Count->addIncoming(BitSizePlusOne, Compute); 380 381 // Next, get the value that we are shifting. 382 PHINode *BitsToShift = new PHINode(Val->getType(), "val", Reverse); 383 BitsToShift->reserveOperandSpace(2); 384 BitsToShift->addIncoming(FRes, Compute); 385 386 // Finally, get the result of the last computation 387 PHINode *RRes = new PHINode(Val->getType(), "rres", Reverse); 388 RRes->reserveOperandSpace(2); 389 RRes->addIncoming(Zero, Compute); 390 391 // Decrement the counter 392 Instruction *Decr = BinaryOperator::createSub(Count, One, "decr", Reverse); 393 Count->addIncoming(Decr, Reverse); 394 395 // Compute the Bit that we want to move 396 Instruction *Bit = 397 BinaryOperator::createAnd(BitsToShift, One, "bit", Reverse); 398 399 // Compute the new value for next iteration. 400 Instruction *NewVal = 401 BinaryOperator::createLShr(BitsToShift, One, "rshift", Reverse); 402 BitsToShift->addIncoming(NewVal, Reverse); 403 404 // Shift the bit into the low bits of the result. 405 Instruction *NewRes = 406 BinaryOperator::createShl(RRes, One, "lshift", Reverse); 407 NewRes = BinaryOperator::createOr(NewRes, Bit, "addbit", Reverse); 408 RRes->addIncoming(NewRes, Reverse); 409 410 // Terminate loop if we've moved all the bits. 411 ICmpInst *Cond = 412 new ICmpInst(ICmpInst::ICMP_EQ, Decr, Zero, "cond", Reverse); 413 new BranchInst(RsltBlk, Reverse, Cond, Reverse); 414 415 // Finally, in the result block, select one of the two results with a PHI 416 // node and return the result; 417 CurBB = RsltBlk; 418 PHINode *BitSelect = new PHINode(Val->getType(), "part_select", CurBB); 419 BitSelect->reserveOperandSpace(2); 420 BitSelect->addIncoming(FRes, Compute); 421 BitSelect->addIncoming(NewRes, Reverse); 422 new ReturnInst(BitSelect, CurBB); 423 } 424 425 // Return a call to the implementation function 426 Value *Args[] = { 427 CI->getOperand(1), 428 CI->getOperand(2), 429 CI->getOperand(3) 430 }; 431 return new CallInst(F, Args, array_endof(Args), CI->getName(), CI); 432} 433 434/// Convert the llvm.part.set.iX.iY.iZ intrinsic. This intrinsic takes 435/// four integer arguments (iAny %Value, iAny %Replacement, i32 %Low, i32 %High) 436/// The first two arguments can be any bit width. The result is the same width 437/// as %Value. The operation replaces bits between %Low and %High with the value 438/// in %Replacement. If %Replacement is not the same width, it is truncated or 439/// zero extended as appropriate to fit the bits being replaced. If %Low is 440/// greater than %High then the inverse set of bits are replaced. 441/// @brief Lowering of llvm.bit.part.set intrinsic. 442static Instruction *LowerPartSet(CallInst *CI) { 443 // Make sure we're dealing with a part select intrinsic here 444 Function *F = CI->getCalledFunction(); 445 const FunctionType *FT = F->getFunctionType(); 446 if (!F->isDeclaration() || !FT->getReturnType()->isInteger() || 447 FT->getNumParams() != 4 || !FT->getParamType(0)->isInteger() || 448 !FT->getParamType(1)->isInteger() || !FT->getParamType(2)->isInteger() || 449 !FT->getParamType(3)->isInteger()) 450 return CI; 451 452 // Get the intrinsic implementation function by converting all the . to _ 453 // in the intrinsic's function name and then reconstructing the function 454 // declaration. 455 std::string Name(F->getName()); 456 for (unsigned i = 4; i < Name.length(); ++i) 457 if (Name[i] == '.') 458 Name[i] = '_'; 459 Module* M = F->getParent(); 460 F = cast<Function>(M->getOrInsertFunction(Name, FT)); 461 F->setLinkage(GlobalValue::WeakLinkage); 462 463 // If we haven't defined the impl function yet, do so now 464 if (F->isDeclaration()) { 465 // Get the arguments for the function. 466 Function::arg_iterator args = F->arg_begin(); 467 Value* Val = args++; Val->setName("Val"); 468 Value* Rep = args++; Rep->setName("Rep"); 469 Value* Lo = args++; Lo->setName("Lo"); 470 Value* Hi = args++; Hi->setName("Hi"); 471 472 // Get some types we need 473 const IntegerType* ValTy = cast<IntegerType>(Val->getType()); 474 const IntegerType* RepTy = cast<IntegerType>(Rep->getType()); 475 uint32_t ValBits = ValTy->getBitWidth(); 476 uint32_t RepBits = RepTy->getBitWidth(); 477 478 // Constant Definitions 479 ConstantInt* RepBitWidth = ConstantInt::get(Type::Int32Ty, RepBits); 480 ConstantInt* RepMask = ConstantInt::getAllOnesValue(RepTy); 481 ConstantInt* ValMask = ConstantInt::getAllOnesValue(ValTy); 482 ConstantInt* One = ConstantInt::get(Type::Int32Ty, 1); 483 ConstantInt* ValOne = ConstantInt::get(ValTy, 1); 484 ConstantInt* Zero = ConstantInt::get(Type::Int32Ty, 0); 485 ConstantInt* ValZero = ConstantInt::get(ValTy, 0); 486 487 // Basic blocks we fill in below. 488 BasicBlock* entry = new BasicBlock("entry", F, 0); 489 BasicBlock* large = new BasicBlock("large", F, 0); 490 BasicBlock* small = new BasicBlock("small", F, 0); 491 BasicBlock* reverse = new BasicBlock("reverse", F, 0); 492 BasicBlock* result = new BasicBlock("result", F, 0); 493 494 // BASIC BLOCK: entry 495 // First, get the number of bits that we're placing as an i32 496 ICmpInst* is_forward = 497 new ICmpInst(ICmpInst::ICMP_ULT, Lo, Hi, "", entry); 498 SelectInst* Hi_pn = new SelectInst(is_forward, Hi, Lo, "", entry); 499 SelectInst* Lo_pn = new SelectInst(is_forward, Lo, Hi, "", entry); 500 BinaryOperator* NumBits = BinaryOperator::createSub(Hi_pn, Lo_pn, "",entry); 501 NumBits = BinaryOperator::createAdd(NumBits, One, "", entry); 502 // Now, convert Lo and Hi to ValTy bit width 503 if (ValBits > 32) { 504 Lo = new ZExtInst(Lo_pn, ValTy, "", entry); 505 } else if (ValBits < 32) { 506 Lo = new TruncInst(Lo_pn, ValTy, "", entry); 507 } 508 // Determine if the replacement bits are larger than the number of bits we 509 // are replacing and deal with it. 510 ICmpInst* is_large = 511 new ICmpInst(ICmpInst::ICMP_ULT, NumBits, RepBitWidth, "", entry); 512 new BranchInst(large, small, is_large, entry); 513 514 // BASIC BLOCK: large 515 Instruction* MaskBits = 516 BinaryOperator::createSub(RepBitWidth, NumBits, "", large); 517 MaskBits = CastInst::createIntegerCast(MaskBits, RepMask->getType(), 518 false, "", large); 519 BinaryOperator* Mask1 = 520 BinaryOperator::createLShr(RepMask, MaskBits, "", large); 521 BinaryOperator* Rep2 = BinaryOperator::createAnd(Mask1, Rep, "", large); 522 new BranchInst(small, large); 523 524 // BASIC BLOCK: small 525 PHINode* Rep3 = new PHINode(RepTy, "", small); 526 Rep3->reserveOperandSpace(2); 527 Rep3->addIncoming(Rep2, large); 528 Rep3->addIncoming(Rep, entry); 529 Value* Rep4 = Rep3; 530 if (ValBits > RepBits) 531 Rep4 = new ZExtInst(Rep3, ValTy, "", small); 532 else if (ValBits < RepBits) 533 Rep4 = new TruncInst(Rep3, ValTy, "", small); 534 new BranchInst(result, reverse, is_forward, small); 535 536 // BASIC BLOCK: reverse (reverses the bits of the replacement) 537 // Set up our loop counter as a PHI so we can decrement on each iteration. 538 // We will loop for the number of bits in the replacement value. 539 PHINode *Count = new PHINode(Type::Int32Ty, "count", reverse); 540 Count->reserveOperandSpace(2); 541 Count->addIncoming(NumBits, small); 542 543 // Get the value that we are shifting bits out of as a PHI because 544 // we'll change this with each iteration. 545 PHINode *BitsToShift = new PHINode(Val->getType(), "val", reverse); 546 BitsToShift->reserveOperandSpace(2); 547 BitsToShift->addIncoming(Rep4, small); 548 549 // Get the result of the last computation or zero on first iteration 550 PHINode *RRes = new PHINode(Val->getType(), "rres", reverse); 551 RRes->reserveOperandSpace(2); 552 RRes->addIncoming(ValZero, small); 553 554 // Decrement the loop counter by one 555 Instruction *Decr = BinaryOperator::createSub(Count, One, "", reverse); 556 Count->addIncoming(Decr, reverse); 557 558 // Get the bit that we want to move into the result 559 Value *Bit = BinaryOperator::createAnd(BitsToShift, ValOne, "", reverse); 560 561 // Compute the new value of the bits to shift for the next iteration. 562 Value *NewVal = BinaryOperator::createLShr(BitsToShift, ValOne,"", reverse); 563 BitsToShift->addIncoming(NewVal, reverse); 564 565 // Shift the bit we extracted into the low bit of the result. 566 Instruction *NewRes = BinaryOperator::createShl(RRes, ValOne, "", reverse); 567 NewRes = BinaryOperator::createOr(NewRes, Bit, "", reverse); 568 RRes->addIncoming(NewRes, reverse); 569 570 // Terminate loop if we've moved all the bits. 571 ICmpInst *Cond = new ICmpInst(ICmpInst::ICMP_EQ, Decr, Zero, "", reverse); 572 new BranchInst(result, reverse, Cond, reverse); 573 574 // BASIC BLOCK: result 575 PHINode *Rplcmnt = new PHINode(Val->getType(), "", result); 576 Rplcmnt->reserveOperandSpace(2); 577 Rplcmnt->addIncoming(NewRes, reverse); 578 Rplcmnt->addIncoming(Rep4, small); 579 Value* t0 = CastInst::createIntegerCast(NumBits,ValTy,false,"",result); 580 Value* t1 = BinaryOperator::createShl(ValMask, Lo, "", result); 581 Value* t2 = BinaryOperator::createNot(t1, "", result); 582 Value* t3 = BinaryOperator::createShl(t1, t0, "", result); 583 Value* t4 = BinaryOperator::createOr(t2, t3, "", result); 584 Value* t5 = BinaryOperator::createAnd(t4, Val, "", result); 585 Value* t6 = BinaryOperator::createShl(Rplcmnt, Lo, "", result); 586 Value* Rslt = BinaryOperator::createOr(t5, t6, "part_set", result); 587 new ReturnInst(Rslt, result); 588 } 589 590 // Return a call to the implementation function 591 Value *Args[] = { 592 CI->getOperand(1), 593 CI->getOperand(2), 594 CI->getOperand(3), 595 CI->getOperand(4) 596 }; 597 return new CallInst(F, Args, array_endof(Args), CI->getName(), CI); 598} 599 600 601void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) { 602 Function *Callee = CI->getCalledFunction(); 603 assert(Callee && "Cannot lower an indirect call!"); 604 605 switch (Callee->getIntrinsicID()) { 606 case Intrinsic::not_intrinsic: 607 cerr << "Cannot lower a call to a non-intrinsic function '" 608 << Callee->getName() << "'!\n"; 609 abort(); 610 default: 611 cerr << "Error: Code generator does not support intrinsic function '" 612 << Callee->getName() << "'!\n"; 613 abort(); 614 615 // The setjmp/longjmp intrinsics should only exist in the code if it was 616 // never optimized (ie, right out of the CFE), or if it has been hacked on 617 // by the lowerinvoke pass. In both cases, the right thing to do is to 618 // convert the call to an explicit setjmp or longjmp call. 619 case Intrinsic::setjmp: { 620 static Constant *SetjmpFCache = 0; 621 Value *V = ReplaceCallWith("setjmp", CI, CI->op_begin()+1, CI->op_end(), 622 Type::Int32Ty, SetjmpFCache); 623 if (CI->getType() != Type::VoidTy) 624 CI->replaceAllUsesWith(V); 625 break; 626 } 627 case Intrinsic::sigsetjmp: 628 if (CI->getType() != Type::VoidTy) 629 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 630 break; 631 632 case Intrinsic::longjmp: { 633 static Constant *LongjmpFCache = 0; 634 ReplaceCallWith("longjmp", CI, CI->op_begin()+1, CI->op_end(), 635 Type::VoidTy, LongjmpFCache); 636 break; 637 } 638 639 case Intrinsic::siglongjmp: { 640 // Insert the call to abort 641 static Constant *AbortFCache = 0; 642 ReplaceCallWith("abort", CI, CI->op_end(), CI->op_end(), 643 Type::VoidTy, AbortFCache); 644 break; 645 } 646 case Intrinsic::ctpop: 647 CI->replaceAllUsesWith(LowerCTPOP(CI->getOperand(1), CI)); 648 break; 649 650 case Intrinsic::bswap: 651 CI->replaceAllUsesWith(LowerBSWAP(CI->getOperand(1), CI)); 652 break; 653 654 case Intrinsic::ctlz: 655 CI->replaceAllUsesWith(LowerCTLZ(CI->getOperand(1), CI)); 656 break; 657 658 case Intrinsic::cttz: { 659 // cttz(x) -> ctpop(~X & (X-1)) 660 Value *Src = CI->getOperand(1); 661 Value *NotSrc = BinaryOperator::createNot(Src, Src->getName()+".not", CI); 662 Value *SrcM1 = ConstantInt::get(Src->getType(), 1); 663 SrcM1 = BinaryOperator::createSub(Src, SrcM1, "", CI); 664 Src = LowerCTPOP(BinaryOperator::createAnd(NotSrc, SrcM1, "", CI), CI); 665 CI->replaceAllUsesWith(Src); 666 break; 667 } 668 669 case Intrinsic::part_select: 670 CI->replaceAllUsesWith(LowerPartSelect(CI)); 671 break; 672 673 case Intrinsic::part_set: 674 CI->replaceAllUsesWith(LowerPartSet(CI)); 675 break; 676 677 case Intrinsic::stacksave: 678 case Intrinsic::stackrestore: { 679 static bool Warned = false; 680 if (!Warned) 681 cerr << "WARNING: this target does not support the llvm.stack" 682 << (Callee->getIntrinsicID() == Intrinsic::stacksave ? 683 "save" : "restore") << " intrinsic.\n"; 684 Warned = true; 685 if (Callee->getIntrinsicID() == Intrinsic::stacksave) 686 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 687 break; 688 } 689 690 case Intrinsic::returnaddress: 691 case Intrinsic::frameaddress: 692 cerr << "WARNING: this target does not support the llvm." 693 << (Callee->getIntrinsicID() == Intrinsic::returnaddress ? 694 "return" : "frame") << "address intrinsic.\n"; 695 CI->replaceAllUsesWith(ConstantPointerNull::get( 696 cast<PointerType>(CI->getType()))); 697 break; 698 699 case Intrinsic::prefetch: 700 break; // Simply strip out prefetches on unsupported architectures 701 702 case Intrinsic::pcmarker: 703 break; // Simply strip out pcmarker on unsupported architectures 704 case Intrinsic::readcyclecounter: { 705 cerr << "WARNING: this target does not support the llvm.readcyclecoun" 706 << "ter intrinsic. It is being lowered to a constant 0\n"; 707 CI->replaceAllUsesWith(ConstantInt::get(Type::Int64Ty, 0)); 708 break; 709 } 710 711 case Intrinsic::dbg_stoppoint: 712 case Intrinsic::dbg_region_start: 713 case Intrinsic::dbg_region_end: 714 case Intrinsic::dbg_func_start: 715 case Intrinsic::dbg_declare: 716 break; // Simply strip out debugging intrinsics 717 718 case Intrinsic::eh_exception: 719 case Intrinsic::eh_selector_i32: 720 case Intrinsic::eh_selector_i64: 721 CI->replaceAllUsesWith(Constant::getNullValue(CI->getType())); 722 break; 723 724 case Intrinsic::eh_typeid_for_i32: 725 case Intrinsic::eh_typeid_for_i64: 726 // Return something different to eh_selector. 727 CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1)); 728 break; 729 730 case Intrinsic::var_annotation: 731 break; // Strip out annotate intrinsic 732 733 case Intrinsic::memcpy_i32: 734 case Intrinsic::memcpy_i64: { 735 static Constant *MemcpyFCache = 0; 736 Value *Size = CI->getOperand(3); 737 const Type *IntPtr = TD.getIntPtrType(); 738 if (Size->getType()->getPrimitiveSizeInBits() < 739 IntPtr->getPrimitiveSizeInBits()) 740 Size = new ZExtInst(Size, IntPtr, "", CI); 741 else if (Size->getType()->getPrimitiveSizeInBits() > 742 IntPtr->getPrimitiveSizeInBits()) 743 Size = new TruncInst(Size, IntPtr, "", CI); 744 Value *Ops[3]; 745 Ops[0] = CI->getOperand(1); 746 Ops[1] = CI->getOperand(2); 747 Ops[2] = Size; 748 ReplaceCallWith("memcpy", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 749 MemcpyFCache); 750 break; 751 } 752 case Intrinsic::memmove_i32: 753 case Intrinsic::memmove_i64: { 754 static Constant *MemmoveFCache = 0; 755 Value *Size = CI->getOperand(3); 756 const Type *IntPtr = TD.getIntPtrType(); 757 if (Size->getType()->getPrimitiveSizeInBits() < 758 IntPtr->getPrimitiveSizeInBits()) 759 Size = new ZExtInst(Size, IntPtr, "", CI); 760 else if (Size->getType()->getPrimitiveSizeInBits() > 761 IntPtr->getPrimitiveSizeInBits()) 762 Size = new TruncInst(Size, IntPtr, "", CI); 763 Value *Ops[3]; 764 Ops[0] = CI->getOperand(1); 765 Ops[1] = CI->getOperand(2); 766 Ops[2] = Size; 767 ReplaceCallWith("memmove", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 768 MemmoveFCache); 769 break; 770 } 771 case Intrinsic::memset_i32: 772 case Intrinsic::memset_i64: { 773 static Constant *MemsetFCache = 0; 774 Value *Size = CI->getOperand(3); 775 const Type *IntPtr = TD.getIntPtrType(); 776 if (Size->getType()->getPrimitiveSizeInBits() < 777 IntPtr->getPrimitiveSizeInBits()) 778 Size = new ZExtInst(Size, IntPtr, "", CI); 779 else if (Size->getType()->getPrimitiveSizeInBits() > 780 IntPtr->getPrimitiveSizeInBits()) 781 Size = new TruncInst(Size, IntPtr, "", CI); 782 Value *Ops[3]; 783 Ops[0] = CI->getOperand(1); 784 // Extend the amount to i32. 785 Ops[1] = new ZExtInst(CI->getOperand(2), Type::Int32Ty, "", CI); 786 Ops[2] = Size; 787 ReplaceCallWith("memset", CI, Ops, Ops+3, CI->getOperand(1)->getType(), 788 MemsetFCache); 789 break; 790 } 791 case Intrinsic::sqrt: { 792 static Constant *sqrtfFCache = 0; 793 static Constant *sqrtFCache = 0; 794 static Constant *sqrtLDCache = 0; 795 switch (CI->getOperand(1)->getType()->getTypeID()) { 796 default: assert(0 && "Invalid type in sqrt"); abort(); 797 case Type::FloatTyID: 798 ReplaceCallWith("sqrtf", CI, CI->op_begin()+1, CI->op_end(), 799 Type::FloatTy, sqrtfFCache); 800 break; 801 case Type::DoubleTyID: 802 ReplaceCallWith("sqrt", CI, CI->op_begin()+1, CI->op_end(), 803 Type::DoubleTy, sqrtFCache); 804 break; 805 case Type::X86_FP80TyID: 806 case Type::FP128TyID: 807 case Type::PPC_FP128TyID: 808 ReplaceCallWith("sqrtl", CI, CI->op_begin()+1, CI->op_end(), 809 CI->getOperand(1)->getType(), sqrtLDCache); 810 break; 811 } 812 break; 813 } 814 } 815 816 assert(CI->use_empty() && 817 "Lowering should have eliminated any uses of the intrinsic call!"); 818 CI->eraseFromParent(); 819} 820